Sura al-Naḥl 16:91

وَأَوْفُوا۟ بِعَهْدِ ٱللَّـهِ إِذَا عَٰهَدتُّمْ وَلَا تَنقُضُوا۟ ٱلْأَيْمَٰنَ بَعْدَ تَوْكِيدِهَا وَقَدْ جَعَلْتُمُ ٱللَّـهَ عَلَيْكُمْ كَفِيلًا إِنَّ ٱللَّـهَ يَعْلَمُ مَا تَفْعَلُونَ

wa-awfū biʿahdi allāhi idhā ʿāhadttum wa-lā tanquḍū l-aymāna baʿda tawkīdihā wa-qad jaʿaltumu allāha ʿalaykum kafīlan inna allāha yaʿlamu mā tafʿalūna

Fulfil the Covenant of Allah when ye have entered into it, and break not your oaths after ye have confirmed them; indeed ye have made Allah your surety; for Allah knoweth all that ye do.