Verse 91

وَأَوْفُوا۟ بِعَهْدِ ٱللَّهِ إِذَا عَـٰهَدتُّمْ وَلَا تَنقُضُوا۟ ٱلْأَيْمَـٰنَ بَعْدَ تَوْكِيدِهَا وَقَدْ جَعَلْتُمُ ٱللَّهَ عَلَيْكُمْ كَفِيلًا إِنَّ ٱللَّهَ يَعْلَمُ مَا تَفْعَلُونَ

And you shall fulfill your covenant to God once you make a covenant, and do not break your oath after you have solemnly taken one, for you have indeed made God a guarantor. Indeed God knows what you are doing.