‘Abd Allaah bin Mas’ud said “Fosterage is not valid except by what strengthens love and grows flesh.” Abu Musa said “Do not ask us so long as this learned man is among us”
Sunan Abi Dawud Book 12, Hadith 14
← Previous Hadith A’ishah said the Apostle of Allaah(ﷺ) visited her when a man was with her. The narrator Hafs said “this grieved him and he frowned”. The agreed version then goes, She said “He is my foster brother Apostle of Allaah(ﷺ)”. He said “Consider, who are you brethren, for fosterage is consequent on hunger.”

Sunan Abi Dawud Book 12, Hadith 13 Next Hadith → The aforesaid tradition has also been narrated by Ibn Mas’ud through a different chain of narrators and to the same effect from the Prophet (ﷺ). This version has the words anshaz al-‘azma meaning which nourishes bones and makes them sturdy and vigorous.

Sunan Abi Dawud Book 12, Hadith 15