הַיֹּֽשְׁבִים֙ בַּקְּבָרִ֔ים וּבַנְּצוּרִ֖ים יָלִ֑ינוּ הָאֹֽכְלִים֙ בְּשַׂ֣ר הַחֲזִ֔יר ופרק [וּמְרַ֥ק] פִּגֻּלִ֖ים כְּלֵיהֶֽם׃
װאָס זיצן צװישן די קבֿרים, און אין באַהעלטענישן נעכטיקן זײ; װאָס עסן פֿלײש פֿון חזיר, און זופּ פֿון אומװערדיקײטן איז אין זײערע כּלים;
Rashi
פגול means abominable; similar is (Isaiah 65:4) "and broth of abominable things (פגולים) is in their vessels".
Ibn Ezra
offensive as in, “broth of abominable things is in their vessels” [Isaiah 65:4]. Onkelos translated this word correctly into the Aramaic “meraḥaq”. Some people have wondered how the sacrifice can be of no account once it has been “willingly accepted” [3:5]. Clearly, it is the intention of the sacrificer that determines the acceptance of the sacrifice. Someone who expected to eat from the peace-offering on the third day never intended to bring a valid peace-offering; for the peace-offerings are intrinsically holy, while the offensive leftovers are intrinsically unholy. Moreover, whatever gain he receives from fulfilling the commandment is offset by the loss he suffers from not fulfilling the commandment, in the case of a peace-offering. In the case of a vow, since he did not fulfill his obligation, his original delinquency is reactivated.