‘Abdullah bin ‘Amr (may Allah be pleased with them both) reports that the Messenger of Allah (peace and blessings of Allah be upon him) said:“The seller and the buyer have the option (to cancel the transaction) as long as they have not separated, unless it is a transaction with a stipulated option (khiyar), in which case the right of return remains even after separation. And it is not permissible for the seller to separate from his companion (the buyer) out of fear that he will cancel the sale.” Imam Tirmidhi says:
1- This hadith is Hasan (good),
2- And its meaning is that after the sale, he separates from the buyer out of fear that he will cancel it, and if separation were only by speech, and the buyer had no option after the sale, then this hadith would have no meaning, which is what you (the Prophet) said:“It is not permissible for the seller to separate from the buyer out of fear that he will cancel his sale.”