john 7:37 In the last day, that great day of the feast, Jesus stood and cried, saying, If any man thirst, let him come unto me, and drink. - Free Bible Online

      37-39. the last day, that great day of the feast--the eighth (Le 23:39). It was a sabbath, the last feast day of the year, and distinguished by very remarkable ceremonies. "The generally joyous character of this feast broke out on this day into loud jubilation, particularly at the solemn moment when the priest, as was done on every day of this festival, brought forth, in golden vessels, water from the stream of Siloah, which flowed under the temple-mountain, and solemnly poured it upon the altar. Then the words of Isa 12:3 were sung, With joy shall ye draw water out of the wells of Salvation, and thus the symbolical reference of this act, intimated in Joh 7:39, was expressed" [OLSHAUSEN]. So ecstatic was the joy with which this ceremony was performed--accompanied with sound of trumpets--that it used to be said, "Whoever had not witnessed it had never seen rejoicing at all" [LIGHTFOOT].
      Jesus stood--On this high occasion, then, He who had already drawn all eyes upon Him by His supernatural power and unrivalled teaching--"JESUS stood," probably in some elevated position.
      and cried--as if making proclamation in the audience of all the people.
      If any man thirst, let him come unto me, and drink!--What an offer! The deepest cravings of the human spirit are here, as in the Old Testament, expressed by the figure of "thirst," and the eternal satisfaction of them by "drinking." To the woman of Samaria He had said almost the same thing, and in the same terms (Joh 4:13, 14). But what to her was simply affirmed to her as a fact, is here turned into a world-wide proclamation; and whereas there, the gift by Him of the living water is the most prominent idea--in contrast with her hesitation to give Him the perishable water of Jacob's well--here, the prominence is given to Himself as the Well spring of all satisfaction. He had in Galilee invited all the WEARY AND HEAVY-LADEN of the human family to come under His wing and they should find REST (Mt 11:28), which is just the same deep want, and the same profound relief of it, under another and equally grateful figure. He had in the synagogue of Capernaum (Joh 6:36) announced Himself, in every variety of form, as "the BREAD of Life," and as both able and authorized to appease the "HUNGER," and quench the "THIRST," of all that apply to Him. There is, and there can be, nothing beyond that here. But what was on all those occasions uttered in private, or addressed to a provincial audience, is here sounded forth in the streets of the great religious metropolis, and in language of surpassing majesty, simplicity, and grace. It is just Jehovah's ancient proclamation now sounding forth through human flesh, "HO, EVERY ONE THAT THIRSTETH, COME YE TO THE WATERS, AND HE THAT HATH NO MONEY!" &c. (Isa 55:1). In this light we have but two alternatives; either to say with Caiaphas of Him that uttered such words, "He is guilty of death," or falling down before Him to exclaim with Thomas, " MY LORD AND MY GOD!"

JFB.