The Prophet (ﷺ) said: Knowledge has three categories; anything else is extra; a precise verse, or an established sunnah (practice), or a firm obligatory duty.
Sunan Abi Dawud Book 19, Hadith 1
← Previous Hadith That his father died and left a debt of thirty wasqs of a Jew on him. Jabir asked him to defer, but he refused. Jabir then spoke to the Messenger of Allah (ﷺ) asking him to mediate to him on his behalf. The Messenger of Allah (ﷺ) came to the Jew and spoke to him about taking fruit-dates in lieu of the debt that was on him. But he refused. The Messenger of Allah (ﷺ) asked him to defer (the debt) to him, but he refused. He then narrated the rest of the tradition.

Sunan Abi Dawud Book 18, Hadith 23 Next Hadith → I fell ill, and the Prophet (ﷺ) and Abu Bakr came to me on foot to visit me. As I was unconscious, I could not speak to him. He performed ablution and sprinkled water on me ; so I became conscious. I said: Messenger of Allah, how should I do in my property, as I have sisters? Thereafter the verse about inheritance was revealed: "They ask thee for legal decision. Say: Allah directs (thus) about those who leave no descendants or ascendants as heirs."

Sunan Abi Dawud Book 19, Hadith 2