1 Samuel 17:26

17:26 David asked the men who were standing near him, “What will be done for the man who strikes down this Philistine and frees Israel from this humiliation? For who is this uncircumcised Philistine, that he defies the armies of the living God?”

1 Samuel 17:36

17:36 Your servant has struck down both the lion and the bear. This uncircumcised Philistine will be just like one of them. For he has defied the armies of the living God!”

Genesis 17:11-14

17:11 You must circumcise the flesh of your foreskins. This will be a reminder of the covenant between me and you. 17:12 Throughout your generations every male among you who is eight days old must be circumcised, whether born in your house or bought with money from any foreigner who is not one of your descendants. 17:13 They must indeed be circumcised, whether born in your house or bought with money. The sign of my covenant will be visible in your flesh as a permanent reminder. 17:14 Any uncircumcised male who has not been circumcised in the flesh of his foreskin will be cut off from his people – he has failed to carry out my requirement.”

Joshua 5:3

5:3 So Joshua made flint knives and circumcised the Israelites on the Hill of the Foreskins.