صحيح البخاري

Narrated Anas bin Malik:

(The tribes of) Ril, Dhakwan, 'Usaiya and Bani Lihyan asked Allah's Messenger (ﷺ) to provide them with some men to support them against their enemy. He therefore provided them with seventy men from the Ansar whom we used to call Al-Qurra' in their lifetime. They used to collect wood by daytime and pray at night. When they were at the well of Ma'una, the infidels killed them by betraying them. When this news reached the Prophet (ﷺ) , he said Al-Qunut for one month In the morning prayer, invoking evil upon some of the 'Arab tribes, upon Ril, Dhakwan, 'Usaiya and Bani Libyan. We used to read a verse of the Qur'an revealed in their connection, but later the verse was cancelled. It was: "convey to our people on our behalf the information that we have met our Lord, and He is pleased with us, and has made us pleased." (Anas bin Malik added:) Allah's Prophet said Qunut for one month in the morning prayer, invoking evil upon some of the 'Arab tribes (namely), Ril, Dhakwan, Usaiya, and Bani Libyan. (Anas added:) Those seventy Ansari men were killed at the well of Mauna.