Urwa bin Zubayr reported,

He heard Marwan and Miswar bin Makhrama, may Allah be pleased with them, both reporting from the companions of the Messenger of Allah ﷺ. He said, when Suhayl bin Amr drew up the treaty with the Prophet ﷺ on that day, among the conditions Suhayl bin Amr stipulated upon the Prophet ﷺ was, "No one shall come to you from us, even if he follows your religion, without your returning him to us and leaving him to us."The believers found this distasteful and were deeply troubled by it, but Suhayl refused anything else. So the Prophet ﷺ concluded the treaty with him on those terms. On that day, he returned Abu Jandal to his father Suhayl bin Amr, and during that period he did not refuse to return any man who came to him, even if he was a Muslim.The believing women, however, came as emigrants. Umm Kulthum bint Uqba bin Abu Muayt was among those who went out to the Messenger of Allah ﷺ that day, and she was a young unmarried woman. Her family came asking the Prophet ﷺ to return her to them, but he did not return her to them, because Allah had revealed concerning such women, "O you who have believed, when the believing women come to you as emigrants, examine them. Allah is most knowing as to their faith," up to His statement, "nor are they lawful for them" [Mumtahanah 60:10].

عن عروة بن الزبير

أنه سمع مروان، والمسور بن مخرمة، رضى الله عنهما يخبران عن أصحاب رسول الله ﷺ قال: لما كاتب سهيل بن عمرو يومئذ، كان فيما اشترط سهيل بن عمرو على النبي ﷺ أنه لا يأتيك منا أحد وإن كان على دينك إلا رددته إلينا، وخليت بيننا وبينه. فكره المؤمنون ذلك، وامتعضوا منه، وأبى سهيل إلا ذلك، فكاتبه النبي ﷺ على ذلك، فرد يومئذ ابا جندل على أبيه سهيل بن عمرو، ولم يأته احد من الرجال إلا رده في تلك المدة، وإن كان مسلما، وجاء المؤمنات مهاجرات، وكانت أم كلثوم بنت عقبة بن أبي معيط ممن خرج إلى رسول الله ﷺ يومئذ وهي عاتق، فجاء أهلهايسألون النبي ﷺ أن يرجعها إليهم، فلم يرجعها إليهم لما أنزل الله فيهن: {يأيها الذين ءامنوا إذا جاء كم المؤمنات مهاجرات فأمتحنوهن الله أعلم بإيمنهن} إلى قوله- {ولا هم يحلون لهن} [الممتحنة: ١٠].