Rashi on Leviticus 22:11/רש"י על ויקרא כ״ב:י״א

1וכהן כי יקנה נפש BUT IF THE PRIEST BUY ANY SOUL… [HE MAY EAT OF IT] — This refers to a Canaanitish servant who has been acquired even in respect to his body (not only as regards his work).

2ויליד ביתו AND THEY THAT ARE BORN IN HIS HOUSE — This refers to the children of his maid-servants. A priest's wife may eat תרומה as may be derived from this verse, for she, too, is “an acquisition obtained by his money” (Ketuvot 57b; cf. Mishna Kiddushin 1:1… ‎'האשה נקנית בכסף וכו‎‎‎, one of the ways in which a marriage may be contracted is by the passing of money or its equivalent from the man to the woman. A wife is therefore a קנין כסף). But it may also be derived from another verse (Numbers 18:11) "[the heave-offering…] everyone that is clean in thy house may eat of it”. Thus is it expounded in Sifrei Bamidbar 117 2.