Qur'an 16:91

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

“And fulfill the covenant of Allāh when you have taken it, [O believers], and do not break oaths after their confirmation while you have made Allāh, over you, a security [i.e., witness]. Indeed, Allāh knows what you do.”

An-Nahl 16:91 · Saheeh International