Qur'an 12:66

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

He said: I will not send him with you till ye give me an undertaking in the name of Allah that ye will bring him back to me, unless ye are surrounded. And when they gave him their undertaking he said: Allah is the Warden over what we say.