John Calvin Commentary Numbers 11:29

"And Moses said unto him, Art thou jealous for my sake? would that all Jehovah`s people were prophets, that Jehovah would put his Spirit upon them!" — Numbers 11:29 (ASV)

And Moses said to him, Enviest thou for my sake? This may be understood in two different ways. Some take it as if Moses had said, "It is no business of yours if I have suffered any loss; and if anything is taken from me, it would be mine and not yours to grieve and grudge."

But I think Moses spoke more simply, as if he had said, "Behold, how differently I feel from you; for I, whose cause you suppose yourself to be promoting, should desire that all were endowed with the spirit of prophecy." So that foolish jealousy was admirably rebuked, which would put a restraint upon God’s blessing, so greatly to be desired by every pious mind.

At the same time, we fully perceive the gentleness and humility of Moses, whom no ambition, nor consideration of his personal dignity, prevents from willingly admitting the very lowliest into companionship with himself.

If any should object that it is God’s pleasure, in order to enhance the excellence of the gift, that there should be but few prophets in the Church, and consequently that Moses inconsiderately sought for that which is contrary to God’s counsel in this matter, the reply is easy:

Although the saints acquiesce in His ordinary dispensations and are persuaded that the arrangement He makes is the best, yet it is an act of piety in them to desire to communicate to all others what is given to themselves. They are anxious rather to be last of all than to begrudge perfection to their brethren.

In sum, Moses declares that nothing would be more gratifying to him than that God should diffuse the grace of the spirit of prophecy among the whole people, so that all should be partakers of it, from the least to the greatest.