We don't know all the details, but God was upset with Moses for not circumcising his son. (redeeminggod.com)
If you feel you must circumcise your son for religious reasons, at least be there with your baby so that he doesn't have to suffer the pain without loved ones present to comfort him. (natural-parenting-advice.com)
Thus, now he obediently circumcises his son; only later, on Mount Moriah, will he fully understand what it really means. (firstthings.com)