It is narrated from Sa'id, the father of Ishaq bin Sa'id, that he said: I was with Sayyiduna Ibn Abbas (may Allah be pleased with them both) when a man came to him and cited a distant kinship, so Sayyiduna Ibn Abbas (may Allah be pleased with them both) said that the Messenger of Allah (peace and blessings be upon him) said: "Know your lineages so that you may maintain your ties of kinship; for there is no closeness in a tie of kinship if it is severed, even if it is close, and there is no distance in it if it is maintained, even if it is distant." This hadith is sahih (authentic) on the condition of Imam Bukhari, but neither of the two Shaykhs recorded it. As for Ishaq bin Sa'id (Ibn Amr bin Sa'id bin al-As), Imam Bukhari took most of his narrations from his father.

It is narrated from Sayyiduna Abu Hurayrah (may Allah be pleased with him) that the Messenger of Allah (peace and blessings be upon him) said: "Learn your lineages so that you may maintain your ties of kinship." This hadith also has a shahid (supporting narration) whose source is of the kind used for shawahid; and Muhammad bin Yahya says that Abu al-Asbat al-Harithi means Bishr bin Rafi'.