Then a survivor came and told Abram the Hebrew. Now he was residing by the oaks of Mamre the Amorite, brother of Eshcol and brother of Aner, and they were allies with Abram.
Genesis 14:13 (NASB)
Abram is described as “the Hebrew” here in Genesis 14:13, and it’s the first time this title is used in scripture.
The Midrash suggests this may the origin story of circumcision, and that Mamre is the one who encourages Abram to do it.
Abram is going to meet the King of Salem and give him a tithe.
While there’s no linguistic link between a tithe and circumcision, they seem thematically linked. Financially, a tenth is so little, but it’s so much. Similarly, a man feels this about his foreskin. It’s nothing, but it’s so much.