Charles Ellicott Commentary Numbers 11:17

"And I will come down and talk with thee there: and I will take of the Spirit which is upon thee, and will put it upon them; and they shall bear the burden of the people with thee, that thou bear it not thyself alone." — Numbers 11:17 (ASV)

And I will come down ... — The cloud which hovered over the Tabernacle appears to have descended to the entrance of it (Numbers 11:25). (Numbers 12:5; Deuteronomy 31:15).

I will take of the spirit which is upon thee ... — These words do not imply that there was any diminution of the gifts bestowed upon Moses, but that a portion of those spiritual gifts was bestowed upon the seventy. Rashi compares the mode of bestowal with the manner in which the other lamps of the Sanctuary were lighted at the golden candlestick without diminishing the light from which theirs was taken.