The Levites: Descended from Jacob's Third Son
Source: TTT
Genesis 29:34
Once again Leah conceived and gave birth to a son, and she said, “Now at last my husband will become attached to me, because I have borne him three sons.” So he was named Levi.
Hebrews 7:9, 10
And so to speak, Levi, who collects the tenth, paid the tenth through Abraham. / For when Melchizedek met Abraham, Levi was still in the loin of his ancestor.