صحیح ابن حبان
Ibn Hibban
كتاب البيوع
Book of Sales
ذكر الخبر الدال على أن الفراق في خبر ابن عمر الذي ذكرناه إنما هو فراق الأبدان دون الفراق الذي يكون بالكلام-
Report indicating that "separation" in Ibn Umar's narration means physical, not verbal, separation
2 hadith
Hadith 4914
Sayyiduna Abdullah bin Abbas (may Allah be pleased with them both) narrates this statement of the Noble Prophet (peace and blessings be upon him): "When a person buys something, it becomes binding upon him, and he has the right regarding it over his companion until he separates from him. If he wishes, he may take it, and if he wishes, he may leave it. But if he separates from his companion, then he will no longer have any choice."
Hadith 4915
This narration is also transmitted with another chain from Sayyiduna Abdullah bin Umar (may Allah be pleased with them both).