Commentary for Avodah Zarah 48:19

Two amoraim here connect a Persian word with a Hebrew word. In the quote of R. Yitzchak Nafha the word “devir” is used to mean “book.” This connects with the word in Judges 1:11. R. Ashi says that the Persian word for menstruant “dashtana” is connected with the phrase in Genesis 31 where Rachel says that she is menstruating. This is what we might term a “folk etymology” connecting a word in a foreign language with a familiar word in one’s own language.