Verses with the word foreskin in the Old Testament (9 verses):

Genesis 17:11
And ye shall circumcise the flesh of your foreskin; and it shall be a token of the covenant betwixt me and you.

Genesis 17:14
And the uncircumcised man child whose flesh of his foreskin is not circumcised, that soul shall be cut off from his people; he hath broken my covenant.

Genesis 17:23
And Abraham took Ishmael his son, and all that were born in his house, and all that were bought with his money, every male among the men of Abraham's house; and circumcised the flesh of their foreskin in the selfsame day, as God had said unto him.

Genesis 17:24
And Abraham was ninety years old and nine, when he was circumcised in the flesh of his foreskin.

Genesis 17:25
And Ishmael his son was thirteen years old, when he was circumcised in the flesh of his foreskin.

Exodus 4:25
Then Zipporah took a sharp stone, and cut off the foreskin of her son, and cast it at his feet, and said, Surely a bloody husband art thou to me.

Leviticus 12:3
And in the eighth day the flesh of his foreskin shall be circumcised.

Deuteronomy 10:16
Circumcise therefore the foreskin of your heart, and be no more stiffnecked.

Habakkuk 2:16
Thou art filled with shame for glory: drink thou also, and let thy foreskin be uncovered: the cup of the LORD's right hand shall be turned unto thee, and shameful spewing shall be on thy glory.