Commentaire sur Le Lévitique 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).

ולקח הכהו. ונתן הכהו, “the priest will take personally, and the priest will give personally;” (put it) just as the priest personally performs this rite so he personally performs the other rites connected with this sacrifice. I might have thought that placing the blood on the altar should be performed by some specially designated vessel such as a spoon or something like it. To prevent us from thinking this, the Torah repeats the word הכהן where it did not appear to have been necessary, and adds that the procedure for the sin offering is the same as that for the guilt offering. There were two priests needed for this whole procedure; the first would sprinkle the blood, and the second priest would have to hold the vessel into which the blood had first been poured.

בהן means THUMB.