פירוש על קידושין 113:5

When it comes to the leper’s mitzvoth, inside the Temple there is a mitzvah that enables—his guilt-offering, which allows him to eat sacrifices. Other sacrifices offered in the Temple atone. Outside the Temple, the leper’s bird offerings enable him to enter the camp. And there are other mitzvoth that atone that are performed outside the Temple, namely the breaking of the heifer’s neck. Just as in the first case, the mitzvah that enables is like the mitzvoth that atones, so too with mitzvoth outside the Temple, those that enable are equivalent to those that atone. Just as one may not derive benefit from the heifer whose neck is broken, so too one may not derive benefit from the leper’s bird offerings.