The Messenger of Allah ﷺ camped between Dajnan and Usfan. The polytheists said, "These people have a prayer that is dearer to them than their fathers and their sons, namely the afternoon prayer. So gather your forces and launch a single, decisive attack against them."Then Jibreel came to the Prophet ﷺ and instructed him to divide his companions into two groups. He would lead one group in prayer while the other group stood behind them, keeping watch with their weapons ready. Then the others would come forward and pray one rakah with him, while the first group took up their weapons and stood guard. In this way, each group prayed one rakah, while the Messenger of Allah ﷺ prayed two.
حدثنا محمود بن غيلان حدثنا عبد الصمد بن عبد الوارث حدثنا سعيد بن عبيد الهنائي حدثنا عبد الله بن شقيق
أن رسول الله ﷺ نزل بين ضجنان وعسفان فقال المشركون إن لهؤلاء صلاة هي أحب إليهم من آبائهم وأبنائهم هي العصر فأجمعوا أمركم فميلوا عليهم ميلة واحدة وأن جبريل أتى النبي ﷺ فأمره أن يقسم أصحابه شطرين فيصلي بهم وتقوم طائفة أخرى وراءهم وليأخذوا حذرهم وأسلحتهم ثم يأتي الآخرون ويصلون معه ركعة واحدة ثم يأخذ هؤلاء حذرهم وأسلحتهم فتكون لهم ركعة ركعة ولرسول الله ﷺ ركعتان
[Its chain of transmission is sahih] Nasai narrated it: 174/3, no. 1545 (Prayer of Fear) from the hadith of Abdul-Samad through the same route, and Ibn Hibban graded it sahih, no. 584. There are also narrations on this subject from Abdullah bin Masud, Zayd bin Thabit, Ibn Abbas, Jabir, Abu Ayyash Zurqi, Ibn Umar, Huzaifa, and Abu Bakra [see no. 564], and Sahl bin Abu Hathma [see nos. 565, 566].