Sayyiduna Abdullah bin Umar (may Allah be pleased with them both) narrates this statement of the Noble Prophet (peace and blessings be upon him): "Both parties involved in a transaction retain the right of option regarding the other party as long as they do not separate from each other; however, the ruling of 'Bay' al-Khiyar' (sale with option) is different."
Hadith Referenceصحیح ابن حبان / كتاب البيوع / 4916
Hadith Gradingفضيلة الشيخ الإمام محمد ناصر الدين الألبانيصحيح - «الإرواء» (5/ 154): ق.فضيلة الشيخ العلّامة شُعيب الأرناؤوطإسناده صحيح على شرط الشيخين