Exodus 12:43-46,48 - strangers cannot partake in the ordinance of the passover, but if they are converted, they may. I believe that in this case, that circumcision symbolizes that they have joined the church.

Leviticus 22:10 - strangers cannot partake of the items consecrated to God's servants

Leviticus 22:12 - marrying outside the covenant forfeits rights

Numbers 16:40 - strangers cannot perform priesthood ordinances

Deuteronomy 17:15 - a holy nation has a ruler chosen of God

Ezekiel 44:6 - strangers cannot go into the temple; not just strangers though, but anyone whose heart is not right as well: "No stranger, uncircumcised in heart, nor uncircumcised in flesh, shall enter into my sanctuary, of any stranger that is among the children of Israel."