Genesis 34:22

19 The young man, who was the most respected of all his father’s household, did not hesitate to fulfill this request, because he was delighted with Jacob’s daughter.

20 So Hamor and his son Shechem went to the gate of their city and addressed the men of their city:

21 “These men are at peace with us. Let them live and trade in our land; indeed, it is large enough for them. Let us take their daughters in marriage and give our daughters to them.

22 But only on this condition will the men agree to dwell with us and be one people: if all our men are circumcised as they are.

23 Will not their livestock, their possessions, and all their animals become ours? Only let us consent to them, and they will dwell among us.”

24 All the men who went out of the city gate listened to Hamor and his son Shechem, and every male of the city was circumcised.

25 Three days later, while they were still in pain, two of Jacob’s sons (Dinah’s brothers Simeon and Levi) took their swords, went into the unsuspecting city, and slaughtered every male.