Rashi on Leviticus
לא יאכל קדש [THERE SHALL] NO [LAYMAN] EAT OF THE HOLY THINGS — Scripture is speaking here of the heave-offering (i. e., the word קדש means here תרומה only, and not any holy food) because the whole section (cf. Rashi on v. 7 and 9) is speaking of this.
Rashbam on Leviticus
וכל זר לא יאכל קודש, even relatively low grade sacred produce such as the tithe given to the priest known as תרומה.
Siftei Chakhamim
Or his hired hand. Explanation: Not that the indentured person and the hired hand are kohanim, because cshould [you think that] someone who belongs [to ahis master] for [a period of] years lose his kehunah?