God tells Abraham to circumcise four times from Genesis 17:10-13. I think the repetition and details obliquely refers to four truths of circumcision:

v10 - Circumcise the heart to keep the covenant
v11 - Circumcise the flesh as a sign of the covenant
v12 - Circumcise on the 8th day as a metaphor of rebirth and beginning anew
v13 - Circumcision to show the adoption of foreigners into Abraham's covenant

Note that all of the men of Abraham's household who were circumcised were already considered part of his household before they were circumcised. Circumcision has never created children for Abraham. It is only a sign of what is already done.