Riyad as-Salihin
Riyad as-Salihin 1325
Obligation of Jihad
Arabic hadith text
وعن سهل بن سعد رضي الله عنه قال: قال رسول الله صلى الله عليه وسلم "ثنتان لا تردان، أو قلما تردان: الدعاء عند النداء وعند البأس حين يلحم بعضهم بعضًا" ((رواه أبو داود بإسناد صحيح)).
Translation
Sahl bin Sa'd (May Allah be pleased with him) reported
The Messenger of Allah (ﷺ) said, "Supplications at two times are never turned down (or said, "Are seldom turned down"), a supplication after the Adhan has been proclaimed, and a supplication during the battle combating the enemy."[Abu Dawud].