Abdullah was the son of Abbas, an uncle of the noble Prophet (S). He was born just three years before the Hijrah. When Abdullah reached the age of discretion, he attached himself to the service of the Prophet (S). He would run to fetch water for him when he wanted to make wudhu. During Salat, he would stand behind the Prophet (S) in prayer and when the Prophet (S) went on journeys or expeditions, he would follow next in line to him. Abdullah thus became like the shadow of the Prophet (S), constantly in his company. In all these situations he was attentive and alert to whatever the Prophet (S) did and said. His heart was enthusiastic and his young mind was pure and uncluttered, committing the Prophet (S)'s words to memory with the capacity and accuracy of a recording instrument. In this way and through his constant researches later, as we shall see, Abdullah became one of the most learned companions of the Prophet (S), preserving on behalf of later generations of Muslims, the priceless words of the Messenger of Allah (S). It is said that he committed to memory about one thousand, six hundred and sixty sayings of the Prophet (S) which are recorded and authenticated in the collections of al-Bukhari and Muslim. The Prophet (S) would often draw Abdullah as a child close to him, pat him on the shoulder and pray: "O Lord, make him acquire a deep understanding of the religion of Islam and instruct him in the meaning and interpretation of things."
The young Abdullah was to prove time and again that he possessed a wisdom beyond his years. But it was a wisdom that came only with devotion and the dogged pursuit of knowledge both during the Prophet (S)'s lifetime and after his death. During the lifetime of the Prophet (S), Abdullah would not miss any of his assemblies and he would commit to memory whatever he said. After the Prophet (S) passed away, he would take care to go to as many companions as possible especially those who knew the Prophet (S) longer and learn from them what the Prophet (S) had taught them. Whenever he heard that someone knew a hadith of the Prophet (S) which he did not know he would go quickly to him and record it. He would subject whatever he heard to close scrutiny and check it against other reports. He would go to as many as thirty companions to verify a single matter.
As Abdullah's knowledge grew, he grew in stature. Masruq ibn al Ajda said of him: "Whenever I saw Ibn Abbas, I would say: He is the most handsome of men. When he spoke, I would say: He is the most eloquent of men. And when he held a conversation, I would say: He is the most knowledgeable of men." The Khalifah Umar ibn al-Khattab often sought his advice on important matters of state and described him as "the young man of maturity". Sad ibn abi Waqqas described him with these words: "I have never seen someone who was quicker in understanding, who had more knowledge and greater wisdom than Ibn Abbas. I have seen Umar summon him to discuss difficult problems in the presence of veterans of Badr from among the Muhajirin and Ansar. Ibn Abbas would speak and Umar would not disregard what he had to say." It is these qualities which resulted in Abdullah ibn Abbas being known as "the learned man of this Ummah".
Abdullah ibn Abbas was not content to accumulate knowledge. He felt he had a duty to the ummah to educate those in search of knowledge and the general masses of the Muslim community. He turned to teaching and his house became a university - yes, a university in the full sense of the word, a university with specialized teaching but with the difference that there was only one teacher Abdullah ibn Abbas. There was an enthusiastic response to Abdullah's classes. One of his companions described a typical scene in front of his house: "I saw people converging on the roads leading to his house until there was hardly any room in front of his house. I went in and told him about the crowds of people at his door and he said: 'Get me water for wudhu.' He performed wudu and, seating himself, said: 'Go out and say to them: Whoever wants to ask about the Quran and its letters (pronunciation) let him enter.'
This I did and people entered until the house was filled. Whatever he was asked, Abdullah was able to elucidate and even provide additional information to what was asked. Then (to his students) he said: 'Make way for your brothers.'
Then to me he said: 'Go out and say: Who wants to ask about the Quran and its interpretation, let him enter'. Again the house was filled and Abdullah elucidated and provided more information than what was requested."
And so it continued with groups of people coming in to discuss fiqh (jurisprudence), halal and haram issues, inheritance laws, Arabic language, poetry and etymology. To avoid congestion with many groups of people coming to discuss various subjects on a single day, Abdullah decided to devote one day exclusively for a particular discipline. His explanations were precise, clear and logical. His arguments were persuasive and supported by pertinent textual evidence and historical facts.
One occasion when his formidable powers of persuasion was used was during the caliphate of Ali. A large number of supporters of Ali in his stand against Muawiyah had just deserted him. Abdullah ibn Abbas went to Ali and requested permission to speak to them. Ali hesitated fearing that Abdullah would be in danger at their hands but eventually gave way on Abdullah's optimism that nothing untoward would happen. Abdullah went over to the group. They were absorbed in worship. Some were not willing to let him speak but others were prepared to give him a hearing. "Tell me" asked Abdullah, "what grievances have you against the cousin of the Prophet (S), the husband of his daughter and the first of those who believed in him?" "The men proceeded to relate three main complaints against Ali. First, that he appointed men to pass judgment in matters pertaining to the religion of God - meaning that Ali had agreed to accept the arbitration of Abu Musa al-Asbari and Amr ibn al-As in the dispute with Muawiyah. Secondly, that he fought and did not take booty nor prisoners of war. Thirdly, that he did not insist on the title of Amir al-Muminin during the arbitration process although the Muslims had pledged allegiance to him and he was their legitimate amir. To them this was obviously a sign of weakness and a sign that Ali was prepared to bring his legitimate position as Amir al-Muminin into disrepute. In reply, Abdullah asked them that should he cite verses from the Quran and sayings of the Prophet (S) to which they had no objection and which related to their criticisms, would they be prepared to change their position. They replied that they would and Abdullah proceeded: "Regarding your statement that Ali has appointed men to pass judgment in matters pertaining to Allah's religion, Allah Glorified and Exalted is He, says: 'O you who believe! Kill not game while in the sacred precincts or in pilgrim garb. If any of you do so intentionally, the compensation is an offering, of a domestic animal equivalent to the one he killed and adjudged by two just men among." "I adjure you, by God! Is the adjudication by men in matters pertaining to the preservation of their blood and their lives and making peace between them more deserving of attention than adjudication over a rabbit whose value is only a quarter of a dirham?" Their reply was of course that arbitration was more important in the case of preserving Muslim lives and making peace among them than over the killing of game in the sacred precincts for which Allah sanctioned arbitration by men. "Have we then finished with this point?" asked Abdullah and their reply was: "Allahumma, naam - O Lord, yes!" Abdullah went on: "As for your statement that Ali fought and did not take prisoners of war as the Prophet (S) did, do you really desire to take your "mother" Aishah as a captive and treat her as fair game in the way that captives are treated? If your answer is "Yes", then you have fallen into kufr (disbelief). And if you say that she is not your "mother", you would also have fallen into a state of kufr for Allah, Glorified and Exalted is He, has said: 'The Prophet (S) is closer to the believers than their own selves and his wives are their mothers (entitled to respect and consideration).' (The Quran, Surah al-Ahzab, 34:6). "Choose for yourself what you want," said Abdullah and then he asked: "Have we then finished with this point?" and this time too their reply was: "Allahumma, naam - O Lord, yes!" Abdullah went on: "As for your statement that Ali has surrendered the title of Amir al-Muminin, (remember) that the Prophet (S) himself at the time of Hudaybiyyah, demanded that the mushrikin write in the truce which he concluded with them: 'This is what the Messenger of Allah has agreed...' and they retorted: 'If we believed that you were the Messenger of Allah we would not have blocked your way to the Kabah nor would we have fought you. Write instead: 'Muhammad the son of Abdullah.' The Prophet (S) conceded their demand while saying: 'By Allah, I am the Messenger of Allah even if they reject me." At this point Abdullah ibn Abbas asked the dissidents: "Have we then finished with this point? and their reply was once again: "Allahumma, naam - O Lord, yes!" One of the fruits of this verbal challenge in which Abdullah displayed his intimate knowledge of the Quran and the sirah of the Prophet (S) as well as his remarkable powers of argument and persuasion, was that the majority, about twenty thousand men, returned to the ranks of Ali. About four thousand however remained obdurate. These latter came to be known as Kharijites.
The courageous Abdullah showed that he preferred peace above war, and logic against force and violence.. He was also known for his great generosity and hospitality. Some of his contemporaries said of his household: "We have not seen a house which has more food or drink or fruit or knowledge than the house of Ibn Abbas." He had a genuine and abiding concern for people. He was thoughtful and caring. He once said: "When I realize the importance of a verse of God's Book, I would wish that all people should know what I know. "When I hear of a Muslim ruler who deals equitably and rules justly, I am happy on his account and I pray for him... "When I hear of rains which fail on the land of Muslims, that fills me with happiness..."
Abdullah ibn Abbas was constant in his devotions. He kept voluntary fasts regularly and often stayed up at night in Prayer. He would weep while praying and reading the Quran. And when reciting verses dealing with death, resurrection and the life hereafter his voice would be heavy from deep sobbing. He passed away at the age of seventy one in the mountainous city of Taif.