(… يَرْتَعْ وَيَلْعَبْ…) (… that he may eat well and play…): They were herdsmen, so they used to go out to look after the cattle. They proposed to take Yusuf to the fields to play.

(... وَإِنَّا لَهُ لَحَافِظُونَ ) (…  And indeed, we will be his guardians):  They claimed that they will take care of him