إِنَّ ٱلَّذِينَ يُبَايِعُونَكَ إِنَّمَا يُبَايِعُونَ ٱللَّهَ يَدُ ٱللَّهِ فَوْقَ أَيْدِيهِمْ ۚ فَمَن نَّكَثَ فَإِنَّمَا يَنكُثُ عَلَىٰ نَفْسِهِۦ ۖ وَمَنْ أَوْفَىٰ بِمَا عَـٰهَدَ عَلَيْهُ ٱللَّهَ فَسَيُؤْتِيهِ أَجْرًا عَظِيمًا
inna alladhīna yubāyiʿūnaka innamā yubāyiʿūna l-laha yadu l-lahi fawqa aydīhim faman nakatha fa-innamā yankuthu ʿalā nafsihi waman awfā bimā ʿāhada ʿalayhu l-laha fasayu'tīhi ajran ʿaẓīman
Indeed, those who pledge allegiance to you, [O Muḥammad] - they are actually pledging allegiance to Allāh. The hand of Allāh is over their hands. So he who breaks his word only breaks it to the detriment of himself. And he who fulfills that which he has promised Allāh - He will give him a great reward.
— Saheeh International
Those who pledge loyalty to you [Prophet] are actually pledging loyalty to God Himself- God’s hand is placed on theirs––and anyone who breaks his pledge does so to his own detriment: God will give a great reward to the one who fulfils his pledge to Him.
— M. A. S. Abdel Haleem
Verily, those who give Bai‘ah (pledge) to you (O Muhammad صلى الله عليه وسلم) they are giving Bai‘ah (pledge) to Allâh. The Hand of Allâh is over their hands. Then whosoever breaks his pledge, breaks it only to his own harm; and whosoever fulfils what he has covenanted with Allâh, He will bestow on him a great reward.
— Muhammad Muhsin Khan & Muhammad Taqi-ud-Din al-Hilali