Al Quran
English Translation of Al-Quran
[9].Surah At-Taubah [The Repentance]
Ayat 25. Truly Allah has given you victory on many battle fields, and on the Day of Hunain (battle) when you rejoiced at your great number but it availed you naught and the earth, vast as it is, was straitened for you, then you turned back in flight.
Ayat 26. Then Allah did send down His Sakinah (calmness, tranquility and reassurance, etc.) on the Messenger (Muhammad [SAWW](PBUH), and on the believers, and sent down forces (angels) which you saw not, and punished the disbelievers. Such is the recompense of disbelievers.
Ayat 27. Then after that Allah will accept the repentance of whom He will. And Allah is Oft-Forgiving, Most Merciful.
Hadith
English Translation of Hadith
Hazrat Anas (May Allah be pleased with him) reported: Whenever the Messenger of Allah [SAWW](PBUH) set out to participate in Jihad, he would supplicate: "Allahumma Anta `adudi wa nasiri, bika ahulu, wa bika asulu, wa bika uqatilu (O Allah, You are my Supporter and my Helper. With Your help I get strength, and with Your help I bounce upon the enemy and defeat it, and with Your help I fight).''
[Abu Dawud Hadith # 2632 and At-Tirmidhi Hadith # 3584].
Lesson : as mentioned above in Surah At-Taubah Ayat 26. "(Allah) sent down forces (angels) which you saw not, and punished the disbelievers. Such is the recompense of disbelievers". Along with the physical resources for war, one should also pray for victory, and for that, it is essential that one submits to Allah, remembers Him and seeks His Help. Prayer is a great source of strength and support for a Muslim and he must make full use of it. The Hadith also teaches us what to say when one sets out for Jihad.