Musannaf Ibn Abi Shaybah 23790 — A man who said to another: Sell your

It is narrated from Ibrahim that if a slave says to his master: Sell me to so-and-so for such-and-such, and you will have 500 dirhams due from me; or if a man comes as guarantor and says: Sell your slave to so-and-so, and you will have 500 dirhams; is it right to say this? He said: This condition is void.