"A Gentile (stranger) is by definition not "one that is born in the land", unless he is a slave in Israel, that was bought with silver and circumcised by their Israelite master. Once circumcised, that slave may eat of the Passover sacrifice. As Gentiles grafted into Israel, we were not bought by silver or gold. Peter explains:"

In the Torah a stranger (ger) is someone who lives in the borders of Israel but is not a citizen, is not an Israelite. It would be like someone coming to be a resident in America from another country and working there but not permanently, unless later they changed their mind and applied for it and were accepted and went through the process of becoming a citizen, which in the Torah would be getting circumcised and observing the Passover.

There is nothing here about slaves. And there is nothing here about a purchase. That matter of slaves wanting to keep the Passover was already finished. It is now talking about strangers, which are not limited to slaves.

It goes on to state that NO uncircumcised person is allowed to eat of the Passover.

Abraham and his whole household getting circumcised is further proof that circumcision in not limited to 8 day year old children. That is just when it is mandatory for children to be circumcised and not any earlier because any day before that and they will bleed to that. And circumcision is important as the sign of the covenant and that is why one is not to delay it extra days after or else face being cut off.