Midrash su Giobbe 40:23

You who are present today, all of you: You are the existence of this world and the world to come. When the Holy One, blessed be He, will come to give a goodly reward to the righteous, He will show them behemoths that crouch on a thousand mountains; and a thousand mountains will bring up grasses and they will eat. And from where [do we know] that they crouch on a thousand mountains? As it is stated (Psalms 50:11), "The behemoths on a thousand mountains." And they drink all [the water] that the Jordan draws, as it is stated (Job 40:23), "he is certain that he will draw the Jordan to his mouth." Rav Yosef said, "They take one swallow and draw all that the Jordan draws for six months. And it is a full verse (Job 39:24), 'With trembling and anger, he swallows the earth.'" And the Leviathan also crouches upon the deep. In the world to come, the Holy One, blessed be He, says to the ministering angels, "Come and fight with him." But when they descend to fight against him, he suspends his eyes and stares at them. And [then] they fear and flee, as it is stated (Job 41:17), "From his rising do the powers fears, the breakers are lacking." When he seeks to eat, he makes a wave in the sea. And [so] the fish think that it is [bringing] something edible, and they go to it; and he opens his mouth and swallows them. And not one of them escapes, but rather all of them enter into his mouth. And [then] the Holy One, blessed be He, says to the ministering angels, "Cast arrows." And they fling [them] at him, but he pays no attention, but they are rather considered like straw by him - as it is stated (Job 41:20), "The son of the bow does not make him flee." And [then] the Holy One, blessed be He, says to them, "Take projectile stones and hurl them at him." And they do it, but he thinks it is straw - as it is stated (Job 41:21), "The catapult is considered like straw." And if you say, where is he crouching; the Holy One, blessed be He, said, upon the clay that is better than gold - as it is stated (Job 41:22), "he reclines on the broken leaves of clay." And if you say [that] if he seeks to leave, he [can] leave - [hence] we learn to say, "he is enclosed with a narrow (tsar) seal" (Job 41:7) - I have closed in front of him, and sealed across from him and I have even restricted (hetsarti) him. And [so] how do the righteous ones eat [it]? Rather the Holy One, blessed be He, puts a spirit into the behemoths and also into the Leviathan, and they come and fight, one with the other - as it is stated (Job 41:8), "One approaches to the other." This one overturns the ground and quiets the behemoths, and these split the Leviathan. [Then] the righteous ones immediately gather around them, and the Holy One, blessed be He, says to each and every one [to eat]. And [each righteous one] eats according to his reward, as it is stated (Job 40:30), "Will the charmers (chavarim) repast upon him?" - Chizkiyah said, "These are [Torah] colleagues (chaverim)." Another [understanding]: "Will the charmers repast upon him?" - anyone who has charmed himself from doing [evil]. "Will it be divided by the traders?" (Job 40:30) - there are among men those that engage in trade: This one gives fifty gold pieces and this one gives ten; they purchase a pearl and it produces revenue. According to what each and every one gave do they take from the revenue. So did the Holy One, blessed be He, say - "Let anyone that was involved with Torah [study] and with [practice of] the commandments, come and take his reward"; as it is stated (Job 42:2), "There is no one so fierce as to rouse him; [and] who can stand (yityatsev) in front of Me?" Who are the ones that are eating in front of [God]? "You who are present." Said the Holy One, blessed be He, "You stood in front of Me in this world to accept the commandments; so too will I stand you in the world to come"; as it is stated (Isaiah 66:22), "For as the new heaven and the new earth, which I will make, shall stand in front of Me - speaks the Lord - so shall your seed and your name stand." Thus did Rabbi Tanchuma expound.

R. Juda in the name of Rab said further: "The Jordan's course is from the cavern of Pania." There is also a Baraitha to the same effect. The Jordan issues from the cavern of Pania, and flows to the sea of Sipchi, of Tiberias, until it reaches the ocean; thence it flows until it reaches the mouth of the leviathan, as it is said (Job 40, 23) He remaineth quiet, though a Jordan rusheth up to his mouth. Raba b. Ula raised the following objection: "Did not this verse speak of the cattle on the thousand mountains? Therefore," said he, "this verse must be interpreted thus: When are the cattle in question sure that they shall remain alive? When the Jordan reaches the mouth of the leviathan (i.e., as long as leviathan lives, they are also sure with life)."

On the sixth day He brought forth from the earth a beast (Behemoth) which lies stretched out on a thousand hills and every day has its pasture on a thousand hills, and overnight (the verdure) grows of its own account as though he had not touched it, as it is said, "Surely the mountains bring him forth food" (Job 40:20). The waters of the Jordan give him water to drink, for the waters of the Jordan surround all the earth, half thereof (flow) above the earth and the other half below the earth, as it is said, "He is confident, though Jordan swell even to his mouth" (Job 40:23). This (creature) is destined for the day of sacrifice, for the great banquet of the righteous, as it is said, "He only that made him can make his sword to approach unto him" (Job 40:19).