سنن أبي داود

Narrated Hakim b. Hizam:

The Messenger of Allah (ﷺ) as saying: Both parties in a business transaction have a right of option (to annul it) so long as they are not separated ; and if they tell the truth and make everything clear, they will be blessed in their transaction, but it they conceal anything and lie, the blessing on their transaction will be blotted out.

Abu Dawud said: A similar tradition has also been transmitted by Sa'id b. Abi 'Arubah and Hammad. As regards with Hammam, he said in his version: Until they separate or exercise the right of option (to annul the transaction), saying the words of option three times.