The Quran

وَاذكُروا نِعمَةَ اللَّهِ عَلَيكُم وَميثاقَهُ الَّذي واثَقَكُم بِهِ إِذ قُلتُم سَمِعنا وَأَطَعنا ۖ وَاتَّقُوا اللَّهَ ۚ إِنَّ اللَّهَ عَليمٌ بِذاتِ الصُّدورِ

Muhammad Asad

And [always] remember the blessings which God has bestowed upon you, and the solemn pledge by which He bound you to Himself¹ when you said, "We have heard, and we pay heed." Hence, remain conscious of God: verily, God has full knowledge of what is in the hearts [of men].

Lit., "His solemn pledge by which He bound you". Since this pledge is given by the believers to God and not by Him to them, the personal pronoun in "His pledge" can have only one meaning: namely, God's binding thereby the believers to Himself.