Al-Ahzab 33:37 واذ تقول للذي انعم الله عليه وانعمت عليه امسك عليك زوجك واتق الله وتخفي في نفسك ما الله مبديه وتخشى الناس والله احق ان تخشاه فلما قضى زيد منها وطرا زوجناكها لكي لا يكون على المومنين حرج في ازواج ادعيايهم اذا قضوا منهن وطرا وكان امر الله مفعولا ٣٧

(Remember) when you (O Prophet,) were saying to the one who was favored by Allah and favored by you, “Keep your wife to your self, and fear Allah.” And you were concealing in your heart what Allah was going to reveal, and you were fearing people, while Allah is more entitled to be feared by you. So, when Zaid finished his desire for her, We gave her into your marriage, so that there may not be a problem for the believers in marrying wives of their adopted sons, when they finish their desire for them; and Allah’s decree had to be enforced.