( يَا أَيُّهَا الَّذِينَ آمَنُوا إِذَا لَقِيتُمُ الَّذِينَ كَفَرُوا زَحْفًا ) (O you who have believed, when you meet those who disbelieve advancing [for battle]): The Arabic word of (Advancing) refers to moving from one place to the other as a whole.
( فَلَا تُوَلُّوهُمُ الْأَدْبَارَ ) (do not turn to them your backs [in flight]): This is order for the believers not to give their backs to the enemy. This symbolizes bravery. One should never turn his back to his enemy, otherwise they will be defeated.