Steadfastness despite temptation to retreat

إِذْ هَمَّت طَّآئِفَتَانِ مِنكُمْ أَن تَفْشَلَا وَٱللَّهُ وَلِيُّهُمَا ۗ وَعَلَى ٱللَّهِ فَلْيَتَوَكَّلِ ٱلْمُؤْمِنُونَ

When two parties among you were about to lose courage, but Allāh was their ally; and upon Allāh the believers should rely.