Job 40:23

Jesus sanctified Baptism by being Himself baptized. If the Son of God was baptized, what godly man is he that despiseth Baptism? But He was baptized not that He might receive remission of sins, for He was sinless; but being sinless, He was baptized, that He might give to them that are baptized a divine and excellent grace. For since the children are partakers of flesh and blood, He also Himself likewise partook of the same, that having been made partakers of His presence in the flesh we might be made partakers also of His Divine grace: thus Jesus was baptized, that thereby we again by our participation might receive both salvation and honour. According to Job, there was in the waters the dragon that draweth up Jordan into his mouth. Since, therefore, it was necessary to break the heads of the dragon in pieces, He went down and bound the strong one in the waters, that we might receive power to tread upon serpents and scorpions. The beast was great and terrible. No fishing-vessel was able to carry one scale of his tail: destruction ran before him, ravaging all that met him. The Life encountered him, that the mouth of Death might henceforth be stopped, and all we that are saved might say, O death, where is thy sting? O grave, where is thy victory? The sting of death is drawn by Baptism.

For the same reason this animal seeks humid and shady places, he also drinks a lot of water, and so Aristotle says in The History of Animals VII that, "Now an elephant drinks fourteen Macedonian measures of water as a draft and again later another …

He will drink up a river, and will not wonder, and trusteth that Jordan can flow into his mouth. 12. For what is in this place designated by the name of 'river,' except the downward course of the human race, which rises at its birth, as if from the source of its fountain, but passes down, as if flowing to its lowest level at its death? But who are signified by the expression 'Jordan,' except those who have been already imbued with the sacrament of Baptism? For since our Redeemer deigned to be baptized in this river, all who have been baptized must needs be expressed by the name of that stream, in which this very sacrament of Baptism happened to be begun. Because, therefore, this Behemoth has drawn to himself like a river the human race flowing downward from the beginning of the world, even to the times of redemption, but a few Elect ones escaping him, it is now well said; He will drink up a river, and will not wonder. But since even after the coming of the Mediator he seizes some even of the faithful, who neglect to live righteously, it is rightly subjoined; And trusteth that Jordan can flow into his mouth. As if it were plainly said, Before the coming of the Redeemer of the world, he drank up the world without wondering, but, which is far worse, even after the coming of the Redeemer, he trusts that he is able to swallow up some, who have been sealed with the sacrament of Baptism. For he devours some who have been placed in the profession of Christians, because he supplants them by causing error in their faith itself. But others he does not turn aside from the uprightness of the faith, but inclines to the practice of wicked works. Others he is unable to bend as much as he wishes in deeds of impurity, but he inwardly turns them aside from the zeal of their intention; so that, when they sever their minds from charity, whatever they may do outwardly may not be right. […]

River - A great quantity of water, hyperbolically called a river. Hasteth not - He drinks not with fear and caution; but such is his courage, that he fears no enemy either by water or by land.

Behold, he drinketh up a river, and hasteth not,....