When the people of Mecca sent ransoms for their captives, Zaynab sent payment to ransom Abu al-As. Among what she sent was a necklace of hers that had belonged to Khadijah, which Khadijah had given her when she married Abu al-As.She said, "When the Messenger of Allah ﷺ saw the necklace, he was deeply moved by it and said, 'If you see fit to release her captive to her and return to her what is hers, then do so.'"They said, "Yes."The Messenger of Allah ﷺ had taken a pledge from Abu al-As, or Abu al-As had promised him, that he would let Zaynab go to him. So the Messenger of Allah ﷺ sent Zayd bin Haritha and a man from the Ansar, telling them, "Stay in the valley of Yajaj until Zaynab passes by you, then accompany her until you bring her back."
حدثنا عبد الله بن محمد النفيلي حدثنا محمد بن سلمة عن محمد بن إسحق عن يحيى بن عباد عن أبيه عباد بن عبد الله بن الزبير
لما بعث أهل مكة في فداء أسراهم بعثت زينب في فداء أبي العاص بمال وبعثت فيه بقلادة لها كانت عند خديجة أدخلتها بها على أبي العاص قالت فلما رآها رسول الله ﷺ رق لها رقة شديدة وقال إن رأيتم أن تطلقوا لها أسيرها وتردوا عليها الذي لها فقالوا نعم وكان رسول الله ﷺ أخذ عليه أو وعده أن يخلي سبيل زينب إليه وبعث رسول الله ﷺ زيد بن حارثة ورجلا من الأنصار فقال كونا ببطن يأجج حتى تمر بكما زينب فتصحباها حتى تأتيا بها
[Hasan] Ahmad reported it, 6/276, from the hadith of Muhammad bin Ishaq, transmitted through him, and he explicitly stated that he heard it directly. Hakim graded it sahih, 3/236, 324 and 4/44,45, according to the criterion of Muslim, and Dhahabi agreed with him. It is also found in the Sirah of Ibn Hisham, p. 653.