פרשת נח - ע״פ לקוטי שיחות

...Rabbi Yehoshua ben Levi said: A person should never express a crude matter, as the formulation of a verse was distorted by the addition of eight letters rather than have it express a crude matter, as it is stated: “From the pure animals and from the animals that are not pure [asher einena tehora]” (Genesis 7:8). To avoid using the Hebrew term for impure [teme’a], which is four letters: Tet, mem, alef, heh, the verse replaced the term with the euphemism meaning “that are not pure,” which is spelled with twelve letters: Alef, shin, reish; alef, yod, nun, nun, heh; tet, heh, reish, heh.