Surah Anfal
السُّوْرَةُ الْأَنْفَال
Pg 182 Ayah 8:41

8:42 [Remember] when you were on the near side of the valley, and they were on the farther side, and the caravan was lower [in position] than you. If you had made an appointment [to meet], you would have missed the appointment. But [it was] so that Allah might accomplish a matter already destined - that those who perished [through disbelief] would perish upon evidence and those who lived [in faith] would live upon evidence; and indeed, Allah is Hearing and Knowing.

8:43 [Remember, O Muhammad], when Allah showed them to you in your dream as few; and if He had shown them to you as many, you [believers] would have lost courage and would have disputed in the matter [of whether to fight], but Allah saved [you from that]. Indeed, He is Knowing of that within the breasts.

8:44 And [remember] when He showed them to you, when you met, as few in your eyes, and He made you [appear] as few in their eyes so that Allah might accomplish a matter already destined. And to Allah are [all] matters returned.

8:45 O you who have believed, when you encounter a company [from the enemy forces], stand firm and remember Allah much that you may be successful.