Charles Ellicott Commentary John 12:36

"While ye have the light, believe on the light, that ye may become sons of light. These things spake Jesus, and he departed and hid himself from them." — John 12:36 (ASV)

While you have light, believe in the light.—Better, as above, According as you have the light. The words are repeated and placed in the most emphatic position in the sentence.

That you may be the children of light.—Better, that you may become sons of light. (Compare for this phrase Notes on John 17:12; Luke 10:6; Luke 16:8; also Ephesians 5:8.) The thought here is the one familiar in St. John, that the believer should become like Him in whom he believed. Those who believed in the light should receive light, and become themselves centres from which light should radiate to others and illuminate their own paths.

These things spoke Jesus, and departed.—(Compare Note on Luke 21:37.) He retired probably to Bethany.