Calvin stresses how hard it was for Abraham to send his son into banishment, ‘but being accustomed to obey God, he brings into subjection the paternal love, which he is not able wholly to cast aside.’ He rose early in the morning, not wanting to delay carrying out this difficult task, in case his affections overcame him and prevented his obedience.
In this verse you notice there is a comma in the middle. He put the food on her shoulder and the water, and the child. But ‘and the child’ refers back to what is said previously. Please don't visualise the child being put on her shoulder. He is a 17-year-old boy. You don’t put a 17-year-old boy on somebody’s shoulder. There is a comma there. He ‘rose up early in the morning, and took bread, and a bottle of water, and gave it unto Hagar, putting it on her shoulder’, and the child was given to Hagar also.