Quran 48:10 from Surah Al-Fath on Divine Marvels.
إِنَّ ٱلَّذِينَ يُبَايِعُونَكَ إِنَّمَا يُبَايِعُونَ ٱللَّهَ يَدُ ٱللَّهِ فَوۡقَ أَيۡدِيهِمۡۚ فَمَن نَّكَثَ فَإِنَّمَا يَنكُثُ عَلَىٰ نَفۡسِهِۦۖ وَمَنۡ أَوۡفَىٰ بِمَا عَٰهَدَ عَلَيۡهُ ٱللَّهَ فَسَيُؤۡتِيهِ أَجۡرًا عَظِيمٗا
English translation: Indeed those who pledge allegiance to you only they pledge allegiance (to) Allah (The) Hand (of) Allah (is) over their hands Then whoever breaks (his oath) then only he breaks against himself and whoever fulfils what he has covenanted (with) Allah soon He will give him a reward great
Transliteration: inna alladhina yubayi'unaka innama yubayi'una al-laha yadu al-lahi fawqa aydihim faman nakatha fa-innama yankuthu ala nafsihi waman awfa bima ahada alayhu al-laha fasayu'tihi ajran aziman