We set out heading to the Messenger of Allah ﷺ, and Waail bin Hajar was with us. An enemy of his seized him. The people were reluctant to swear an oath, but I swore that he was my brother, so the man let him go.We came to the Messenger of Allah ﷺ, and I mentioned that to him. He said, "You were the most righteous and truthful of them. You spoke the truth. The Muslim is the brother of the Muslim."
حدثنا يزيد بن هارون قال أخبرنا إسرائيل بن يونس بن أبي إسحاق قال حدثنا إبراهيم بن عبد الأعلى عن جدته
خرجنا نريد رسول الله ﷺ ومعنا وائل بن حجر فأخذه عدو له فتحرج الناس أن يحلفوا وحلفت أنه أخي فخلى عنه فأتينا رسول الله ﷺ فذكرت ذلك له فقال أنت كنت أبرهم وأصدقهم صدقت المسلم أخو المسلم
Its isnad is daif due to the unknown status of his grandfather Ibrahim bin Abdul-Ala. It was narrated by Abu Dawud 3/224, no. 3256, in the Book of Oaths, chapter on equivocal expressions in oaths, and in Awn al-Mabud, at the same number, chapter, and book, it says his grandmother is unknown. It is likewise found in Ibn Majah 1/685, no. 2119, in the Book of Expiations, chapter on one who employs equivocation in his oath.