Sifra on Acharei Mot

“Which if a man does.” Rabbi Yirmiyah would say: From where do we know that even a non-Jew who does the Torah is like a Kohen Gadol (the High Priest)? From the fact that is says “which if a man does, he shall live in them.” And so too in another verse, scripture doesn’t say “the Kohens, Levites and Israelites,” rather it says “this is the teaching (Heb. Torah) of man, Adonai is God.” And so too in another verse, scripture doesn’t say “Open the gates and Kohens, Levites and Israelites will come in,” rather it says “the righteous non-Jew guards the faithful.” And so too in another verse, scripture doesn’t say “This is the gate to God, Kohens, Levites and Israelites will enter it,” rather it says “the righteous shall enter it.” And so too with another verse, scripture doesn’t say “Kohens, Levites and Israelites shall rejoice,” rather it says, “the righteous shall rejoice in God.” And so too with another verse, scripture doesn’t say “God will be made great for the Kohens, Levites and Israelites,” rather it says, “God will be made great for those who are good.” Thus, even a non-Jew who does the Torah, behold he is like a Kohen Gadol.