33:15
وَلَقَدْ كَانُوا۟ عَٰهَدُوا۟ ٱللَّهَ مِن قَبْلُ لَا يُوَلُّونَ ٱلْأَدْبَٰرَ ۚ وَكَانَ عَهْدُ ٱللَّهِ مَسْـُٔولًۭا
Wa laqad kaanoo 'aahadul laaha min qablu laa yuwal loonal adbaar; wa kaana 'ahdul laahi mas'oolaa
They had earlier covenanted with Allah that they would not turn their backs in flight. And a covenant made with Allah must needs be answered for.
