Anas bin Malik reported that the tribes of Ril, Zakwan, Usayya, and Banu Lihyan asked the Messenger of Allah ﷺ for support against an enemy, so he sent them seventy of the Ansar to assist. We used to call these men the Reciters in their day. They would gather firewood by day and pray by night. When they reached the well of Mauna, the tribes killed them treacherously. News of this reached the Prophet ﷺ, so he made the qunut supplication for a month, praying during the dawn prayer against those Arab tribes, against Ril, Zakwan, Usayya, and Banu Lihyan.Anas said, "We used to recite a passage of Quran about them, but it was later abrogated. It read, 'Convey to our people on our behalf that we have met our Lord, and He is pleased with us, and we are pleased with Him.'"Qatada reported that Anas bin Malik told him that the Prophet of Allah ﷺ made qunut for a month in the dawn prayer, praying against the Arab tribes, against Ril, Zakwan, Usayya, and Banu Lihyan.
إن رعلا وذكوان وعصية وبني لحيان استمدوا رسول الله ﷺ على عدو، فأمدهم بسبعين من الأنصار كنا نسميهم القراء في زمانهم، كانوا يحتطبون بالنهار، ويصلون بالليل، حتى كانوا ببئر معونة قتلوهم وغدروا بهم، فبلغ ذلك النبي ﷺ فقنت شهرا يدعو في الصبح على أحياء العرب: على رعل وذكوان وعصية وبني لحيان، قال أنس: فقرأنا عليهم قرآنا، ثم إن ذلك رفع: بلغوا عنا قومنا أنا لقينا ربنا فرضي عنا وأرضانا. وعن قتادة، عن أنس بن مالك حدثه أن نبي الله ﷺ قنت شهرا في صلاة الصبح يدعو على أحياء العرب: على رعل وذكوان وعصية وبني لحيان.
Bukhari reported it in the Book of Military Expeditions (4090), from Abdul-Ala bin Hammad, who said, Yazid bin Zuray narrated to us, who said, Saeed narrated to us, from Qatada, from Anas bin Malik, and he mentioned it.Regarding his statement, "they sought reinforcement from the Messenger of Allah ﷺ against an enemy," it appears from this that they came to the Prophet ﷺ seeking help against their enemy, which differs from the preceding context. The two contexts can be reconciled by saying that they came to the Prophet ﷺ and asked him for both things, teaching and then reinforcement, so the Prophet ﷺ sent seventy reciters to them for both teaching and reinforcement together.