An Nahl, 91 Ayah
16:91
وَأَوۡفُواْ بِعَهۡدِ ٱللَّهِ إِذَا عَٰهَدتُّمۡ وَلَا تَنقُضُواْ ٱلۡأَيۡمَٰنَ بَعۡدَ تَوۡكِيدِهَا وَقَدۡ جَعَلۡتُمُ ٱللَّهَ عَلَيۡكُمۡ كَفِيلًاۚ إِنَّ ٱللَّهَ يَعۡلَمُ مَا تَفۡعَلُونَ ٩١
Wa 'Awfū Bi`ahdi Al-Lahi 'Idhā `Āhadtum Wa Lā Tanquđū Al-'Aymāna Ba`da Tawkīdihā Wa Qad Ja`altumu Al-Laha `Alaykum Kafīlāan ۚ 'Inna Al-Laha Ya`lamu Mā Taf`alūna
And fulfill the covenant of Allah when you have taken it, [O believers], and do not break oaths after their confirmation while you have made Allah, over you, a witness. Indeed, Allah knows what you do.