3. Mose (Wajikra) 14:14

תנוך is the inner wall of the ear. The etymology of the word תנוך is unknown to me, and the compilers of glossaries call it (translate it by) tendron (cf. Rashi on Exodus 29:22). בהן means THUMB.

וְלָקַ֣ח הַכֹּהֵן֮ מִדַּ֣ם הָאָשָׁם֒ וְנָתַן֙ הַכֹּהֵ֔ן עַל־תְּנ֛וּךְ אֹ֥זֶן הַמִּטַּהֵ֖ר הַיְמָנִ֑ית וְעַל־בֹּ֤הֶן יָדוֹ֙ הַיְמָנִ֔ית וְעַל־בֹּ֥הֶן רַגְל֖וֹ הַיְמָנִֽית׃

and the priest shall take some of the blood of the guilt offering, and the priest shall put it upon the tip of the right ear of him that is to be cleansed, and upon the thumb of his right hand, and upon the great toe of his right foot: