Exodus 12:43

But the deceitful, and he that is not pure of heart and possesses nothing that is pure (as Proverbs says, "To a deceitful man there is nothing good") shall assuredly, being a stranger and of a different race from the saints, be accounted unworthy to eat the Passover, for "a foreigner shall not eat of it." Thus Judas, when he thought he kept the Passover, because he plotted deceit against the Savior, was estranged from the city which is above and from the apostolic company. For the law commanded the Passover to be eaten with due observance.

And the Lord said unto Moses and Aaron,....

We must be born again by the word ere we can be nourished by it. Nor shall any partake of the benefit of Christ's sacrifice, or feast upon it, who are not first circumcised in heart, Col. ii. Any stranger that was circumcised might be welcome to eat of the passover, even servants,

This is the ordinance of the passover - From the last verse of this chapter it appears pretty evident that this, to the 50th verse inclusive, constituted a part of the directions given to Moses relative to the proper observance of the first passover, and should be read conjointly with the preceding account beginning at Exo 12:21. It may be supposed that these latter parts contain such particular directions as God gave to Moses after he had given those general ones mentioned in the preceding verses, but they seem all to belong to this first passover. There shall no stranger eat thereof - בן נכר ben nechar, the son of a stranger or foreigner, i.e., one who was not of the genuine Hebrew stock, or one who had not received circumcision; for any circumcised person might eat the passover, as the total exclusion extends only to the uncircumcised, see Exo 12:48. As there are two sorts of strangers mentioned in the sacred writings; one who was admitted to all the Jewish ordinances, and another who, though he dwelt among the Jews, was not permitted to eat the passover or partake of any of their solemn feasts; it may be necessary to show what was the essential point of distinction through which the one was admitted and the other excluded. In treatises on the religious customs of the Jews we frequently meet with the term proselyte, from the Greek προσηλυτος, a stranger or foreigner; one who is come from his own people and country to sojourn with another. All who were not descendants of some one of the twelve sons of Jacob, or of Ephraim and Manasseh, the two sons of Joseph, were reputed strangers or proselytes among the Jews. But of those strangers or proselytes there were two kinds, called among them proselytes of the gate, and proselytes of injustice or of the covenant. […]