The Messenger of Allah ﷺ sent us to Idam, so I set out with a group of Muslims, among whom were Abu Qatada Harith bin Rubai and Muhallim bin Jaththama bin Qays. We traveled until we reached the valley of Idam, when Amir al-Ashjai passed by us riding a young camel of his, carrying a few belongings and a waterskin of milk. As he passed, he greeted us with the salaam, but we held back from him, while Muhallim bin Jaththama charged at him and killed him over some grievance between them, then took his camel and his belongings.When we returned to the Messenger of Allah ﷺ and informed him of what had happened, the Quran was revealed concerning us, "You who believe, when you go forth in the cause of Allah, verify carefully, and do not say to one who offers you the greeting of peace, 'You are not a believer,' seeking the fleeting gains of this worldly life, for with Allah are abundant spoils. You were like that before, then Allah bestowed His favor upon you, so verify carefully. Indeed, Allah is ever Aware of what you do" [Nisa 4:94].
حدثنا يعقوب حدثنا أبي عن ابن إسحاق حدثني يزيد بن عبد الله بن قسيط عن القعقاع بن عبد الله بن أبي حدرد
بعثنا رسول الله ﷺ إلى إضم فخرجت في نفر من المسلمين فيهم أبو قتادة الحارث بن ربعي ومحلم بن جثامة بن قيس فخرجنا حتى إذا كنا ببطن إضم مر بنا عامر الأشجعي على قعود له متيع ووطب من لبن فلما مر بنا سلم علينا فأمسكنا عنه وحمل عليه محلم بن جثامة فقتله بشيء كان بينه وبينه وأخذ بعيره ومتيعه فلما قدمنا على رسول الله ﷺ وأخبرناه الخبر نزل فينا القرآن {يا أيها الذين آمنوا إذا ضربتم في سبيل الله فتبينوا ولا تقولوا لمن ألقى إليكم السلام لست مؤمنا تبتغون عرض الحياة الدنيا فعند الله مغانم كثيرة كذلك كنتم من قبل فمن الله عليكم فتبينوا إن الله كان بما تعملون خبيرا}
Its chain of transmission is sahih. Qaqa bin Abdullah bin Abu Hadrad was a companion, though it is also said that he was not a companion. Bukhari related the hadith in Fath al-Bari, 8/258, no. 4591, Abu Dawud, 4/32, no. 3974, and Tirmidhi, 5/240, no. 3030, who graded it hasan. Ibn Jareer Tabari related it in his tafsir, 5/140, and Hakim graded it sahih, 2/235. Bayhaqi also related it in Dalail, 4/305.