Jamieson, Fausset & Brown

He was a burning and a shining light--literally, "the burning and shining lamp" (or torch):--that is, "the great light of his day." Christ is never called by the humble word here applied to John--a light-bearer--studiously used to distinguish him from his Master, but ever the Light in the most absolute sense. (See on Joh 1:6). willing for a season--that is, till they saw that it pointed whither they were not prepared to go. to rejoice in his light--There is a play of irony here, referring to the hollow delight with which his testimony tickled them.