Surah Yusuf — Ayah 63 (12:63)
فَلَمَّا رَجَعُوٓاْ إِلَىٰٓ أَبِيهِمۡ قَالُواْ يَٰٓأَبَانَا مُنِعَ مِنَّا ٱلۡكَيۡلُ فَأَرۡسِلۡ مَعَنَآ أَخَانَا نَكۡتَلۡ وَإِنَّا لَهُۥ لَحَٰفِظُونَ ٦٣
English translation (Saheeh International)
So when they returned to their father, they said, "O our father, [further] measure has been denied to us, so send with us our brother [that] we will be given measure. And indeed, we will be his guardians."
Brief commentary
When they returned to their father, and told him about the generosity of Joseph to them, they also told their father that any further measure would be denied to them if they did not bring their brother with them. They asked him to send him with them, because if he did so they would be given provisions. They promised their father that they would take good care of him, bringing him back safely.