Surah Yusuf, verse 66

قَالَ لَنْ أُرْسِلَهُۥ مَعَكُمْ حَتَّىٰ تُؤْتُونِ مَوْثِقًا مِّنَ ٱللَّهِ لَتَأْتُنَّنِى بِهِۦٓ إِلَّآ أَن يُحَاطَ بِكُمْ ۖ فَلَمَّآ ءَاتَوْهُ مَوْثِقَهُمْ قَالَ ٱللَّهُ عَلَىٰ مَا نَقُولُ وَكِيلٌ ﴿٦٦﴾

12:66 He said, “I will never send him with you unless you give me a pledge by Allah that you will surely bring him back to me, unless you are completely overpowered.” Then when they gave him their pledge, he said, “Allah is Witness to what we say.”