Source and decoding - Bava Kamma 5a
אֶלָּא מִנְיָינָא דְּרַבִּי חִיָּיא, לְמַעוֹטֵי מַאי? לְמַעוֹטֵי מוֹסֵר וּמְפַגֵּל. וְלִיתְנֵי! בִּשְׁלָמָא מְפַגֵּל – בְּקָדָשִׁים לָא קָמַיְירֵי. אֶלָּא מוֹסֵר, מַאי טַעְמָא לָא תָּנֵי? שָׁאנֵי מוֹסֵר – דְּדִיבּוּרָא, וּבְדִיבּוּרָא לָא קָמַיְירֵי.
Rather, the count of Rabbi Chiyya, what does it come to exclude? To exclude an informer and one who invalidates a sacrifice (mefagel). But let him teach them! Granted regarding one who invalidates a sacrifice—he does not deal with consecrated items. But an informer, what is the reason he does not teach him? An informer is different—because he damages by speech, and with speech he does not deal.
The Gemara investigates what Rabbi Chiyya's precise tally of twenty-four tort categories is intended to exclude. It answers that the list deliberately excludes an informer (moser) and a priest who invalidates an offering through illicit intent (mefagel). While informing certainly causes direct monetary loss, it operates solely through verbal communication without physical action. Consequently, the Gemara establishes that primary damage categories focus exclusively on damages produced through physical acts rather than pure speech.