“I heard Anas bin Malik say: ‘We gave our pledge to the Messenger of Allah (ﷺ) on the basis that we would listen and obey. He (ﷺ) said: “As much as you can.”
Sunan Ibn Majah Book 24, Hadith 116
← Previous Hadith “We were with the Prophet (ﷺ) – seven or eight or nine of us – and he said: ‘Will you not give pledge to the Messenger of Allah?’ So we stretched forth our hands and someone said: ‘O Messenger of Allah, we have already given you our pledge. On what basis shall we give this pledge?’ He said: ‘(On the basis that) you will worship Allah and not associate anything with Him, you will establish the five daily prayers, you will listen and obey’ – then he spoke some words under his breath – ‘and you will not ask the people for anything.’ He said: ‘I saw some of that group. If he dropped his whip he would not ask anyone to pick it up for him.’”

Sunan Ibn Majah Book 24, Hadith 115 Next Hadith → “A slave came and gave his pledge to the Prophet (ﷺ), pledging to emigrate, and the Prophet (ﷺ) did not realize that he was a slave. Then his master came looking for him, and the Prophet (ﷺ) said: ‘Sell him to me,’ and he brought him in exchange for two black slaves. Then after that he did not accept the pledge from anyone until he had asked whether he was a slave.”

Sunan Ibn Majah Book 24, Hadith 117