Sayyiduna Abdullah bin Abi Hadrad (may Allah be pleased with him) narrated: The Messenger of Allah sent us towards Idam. I set out with a group of Muslims, among whom were Sayyiduna Abu Qatadah al-Harith bin Rib'i (may Allah be pleased with him) and Sayyiduna Muhallim bin Jaththamah bin Qays (may Allah be pleased with him). We set out, and when we reached the valley of Idam, Amir bin al-Adbat al-Ashja'i passed by us. He was riding his mount, and he had some belongings and a skin of milk with him. When he passed by us, he greeted us with salam. We held back from him, but Muhallim bin Jaththamah attacked him and killed him, because of something that was between the two of them, and he took the man's camel and his belongings. When we came to the Prophet (peace and blessings be upon him), we informed him about this, and this command of the Qur'an was revealed about us:
"O you who believe! When you travel in the way of Allah, verify matters, and do not say to the one who greets you with salam, 'You are not a believer,' seeking the goods of the worldly life, while with Allah Almighty there are abundant spoils. You too were like this before, then Allah Almighty bestowed His favour upon you, so verify matters. Indeed, Allah Almighty is well aware of what you do."
Ahmad and al-Tabarani recorded it, and its narrators are thiqat (trustworthy).
Hadith Referenceمجمع الزوائد ومنبع الفوائد / كتاب التفسير / 10942
Hadith Gradingمحدثین:إسنادہ صحیح
Hadith Takhrij«اخرجه احمد فى المسند (11/6) ، أخرجه مسند أحمد برقم: 23364، وأخرجه الأوسط في السنن والإجماع والاختلاف برقم: 9393، وأخرجه إتحاف الخيرة المهرة بزوائد المسانيد العشرة برقم: 5667/2»