The Prophet (ﷺ) said: Pay the deposit to him who deposited it with you, and do not betray him who betrayed you.
Sunan Abi Dawud Book 24, Hadith 120
← Previous Hadith I used to write (the account of) the expenditure incurred on orphans who were under the guardianship of so-and-so. They cheated him by one thousand dirhams and he paid these (this amount) to them. I then got double the property which they deserved. I said (to the man: Take one thousand (dirhams) which they have taken from you (by cheating). He said: No, my father has told me that he heard the Messenger of Allah (ﷺ) say: Pay the deposit to him who deposited it with you, and do not betray him who betrays you.

Sunan Abi Dawud Book 24, Hadith 119 Next Hadith → That the Prophet (ﷺ) used to accept a gift and make return for it.

Sunan Abi Dawud Book 24, Hadith 121