The 137th prohibition is that a chalalah1 is forbidden from eating those sacred portions she would otherwise be allowed to eat [by virtue of being in the family of a Kohen] — i.e. terumah, the brisket, and the leg [of peace offerings].

The source of this prohibition is G‑d's statement,2 "When a Kohen's daughter marries a non-Kohen, she nay no longer eat the holy terumah."

Our Sages say tractate Yevamos,3 "The verse 'When a Kohen's daughter marries a non-Kohen' indicates that once she has had relations with someone forbidden to her, she becomes forbidden [to eat terumah]."

They interpret the phrase, "she may no longer eat the holy terumah" (terumas hakodashim) as referring to "that which is separated from the sacrifices" — i.e. the brisket, and the leg [of peace offerings].

The passage there states, "The verse could have said 'She may no longer eat kodashim.' Why does it say terumas hakodashim? To teach us two things." The meaning of this statement: the verse teaches [first of all] that once she has had relations with someone forbidden to her, she becomes forbidden to eat terumah; and [secondly] that if she married a non-Kohen and then he died, she can resume eating terumah but no the brisket and the leg.

Therefore this prohibition includes two parts: one that a chalalah may not eat holy offerings; and two, that a Kohen's daughter who married a non-Kohen may not eat the brisket and the leg even if her husband dies or divorces her.

However, the prohibition of eating terumah while she is still married to him is not derived from this verse; but the guardians of the Oral Tradition have learned it from the verse,4 "No non-Kohen may eat kodesh (holy things)." As long as she is married to a non-Kohen she is considered the same as he is, and is therefore the word zar (non-Kohen) refers to her as well. You should keep this in mind, and also that she also receives lashes for violating this prohibition.