Al-Anfal 8:15

Ya ayyuha allatheena amanooitha laqeetumu allatheena kafaroo zahfan falatuwalloohumu al-adbar

O you who have believed, when you meet those who disbelieve advancing [in battle], do not turn to them your backs [in flight].

O you who believe, when you face the disbelievers in a battle, do not turn your backs to them.