Abdullah bin Abbas (may Allah be pleased with him) had an inquiring tongue and an understanding heart

Imam al-Zuhri states that the Muhajirun said to Sayyiduna Umar bin al-Khattab (may Allah be pleased with him): "Invite our sons (to the gathering) as you invite Ibn Abbas (may Allah be pleased with them both)." He said: "He is a youth with the maturity of the middle-aged; he has a tongue that asks much and a heart that understands well."

Ibrahim bin Ikrimah bin Huyayy states: I, Huyayy bin Ya'la and Sa'id bin Jubayr used to go to Sayyiduna Ibn Abbas (may Allah be pleased with them both). I would ask him about genealogies, Huyayy would ask him about the famous battles (Ayyam) of the Arabs, and Sa'id bin Jubayr would ask him about legal rulings, and it felt as though we were drawing from a boundless ocean.

Abdullah bin Shaddad states that Sayyiduna Abdullah bin Abbas (may Allah be pleased with them both) said: "O Ibn Shaddad! Are you not amazed? A servant boy came to me when I had lain down for the midday rest (qaylulah) and said that a man was at the door asking permission to enter. I said (to myself) that only some need would have brought him at this hour; let him in. He came in and said: Will you not tell me about that man? I asked: Which man? He said: Ali bin Abi Talib. I asked: About which matter of his? He said: When will he be raised (brought back to life)? I said: Subhan Allah! He will be raised when those in the graves are raised. Then he said: I see you saying just what these fools say. At that I said: Put him out of my presence, and let him never come to me again, or else I will beat him."
This chain of narration is sahih (authentic) on the condition of the two Shaykhs (Bukhari and Muslim).