Midrasz do Hioba 40:29

“Boaz said to Ruth: Have you not heard, my daughter? Do not go to glean in another field, and also do not pass from here, but cleave to my young women” (Ruth 2:8).
“Boaz said to Ruth: Have you not heard, my daughter? Do not go to glean in another [aḥer] field” – this is on the basis of: “You shall have no other [aḥerim] gods before Me” (Exodus 20:3). “And also do not pass from here [mizeh],” on the basis of: “This [zeh] is my God and I will exalt Him” (Exodus 15:2). “But cleave to my young women” – these are the righteous who are called youth, as it is stated: “Will you play with it as with a bird? Will you bind it for your young women?” (Job 40:29).¹⁶⁷The reference is to the leviathan that God will provide to the righteous in the future. The midrash thus explains the seemingly repetitive phraseology of the verse to mean that Boaz was subtly encouraging Ruth to continue to be a righteous convert.

Rabba said further in the name of R. Jochanan: "The Holy One, praised be He! will make a succah for the righteous from the skin of the leviathan, as it is said (Ib. 31) Canst thou fill his skin with Succoth. If the righteous merits he will have a booth; but if he does not merit he will get a little hut, as it is said (Ib.) And with fist spear his head; and if still less, then a necklace will be made for him, as it is said (Prov. 1, 9) And chains for thy throat; and if still less, an amulet will be made for him, as it is said (Job 40, 29) And tied him up for thy maidens? And tlie remainder of the skin the Lord will spread on the walls of Jerusalem, and the brightness of it will shine from one end of the world to the other, as it is said (Is. 69, 3) and nations shall walk by thy light, and kings by the brightness of thy shining."