Matthew Poole and continuators on Exodus 12:44

44 But every man-servant that is bought for money, when thou hast circumcised him , then shall he eat thereof.

For the master had a power to circumcise such persons, Gen. 17. 12. And though it is probable, that by their interest in them and a diligent instruction of them, they made them willing to receive circumcision, yet it seems they had a power to compel them to it, but then Circumcision was not to them a seal of Gods covenant, nor of their Religion, for that must be matter of choice, but onely a civil badge, or a note of that family or people into which they were politically incorporated.