وَلَقَدْ كَانُوْا عَاهَدُوا اللّٰهَ مِنْ قَبْلُ لَا يُوَلُّوْنَ الْاَدْبَارَ ۗوَكَانَ عَهْدُ اللّٰهِ مَسْـُٔوْلًا ( الأحزاب: ١٥ )
walaqad
وَلَقَدْ
And certainly
kānū
كَانُوا۟
they had
ʿāhadū
عَٰهَدُوا۟
promised
l-laha
ٱللَّهَ
Allah
min
مِن
before
qablu
قَبْلُ
before
lā
لَا
not
yuwallūna
يُوَلُّونَ
they would turn
l-adbāra
ٱلْأَدْبَٰرَۚ
their backs
wakāna
وَكَانَ
And is
ʿahdu
عَهْدُ
(the) promise
l-lahi
ٱللَّهِ
(to) Allah
masūlan
مَسْـُٔولًا
to be questioned
Wa laqad kaanoo 'aahadul laaha min qablu laa yuwal loonal adbaar; wa kaana 'ahdul laahi mas'oolaa (al-ʾAḥzāb 33:15)
Sahih International:
And they had already promised Allah before not to turn their backs [i.e., flee]. And ever is the promise to Allah [that about which one will be] questioned. (Al-Ahzab [33] : 15)
1 Mufti Taqi Usmani
despite that they had already made a covenant with Allah that they would not turn their backs; and a covenant with Allah has to be answered for.