Where is modesty mentioned in the Torah, and is it deoraita (from the Torah)?

Rabbi Shay Tahan

First, let's establish that it's deoraita. The Gemara (Eruvin 100b) tells us: "Rabbi Yochanan said: If the Torah had not been given, we would have learned modesty from a cat." We clearly see that it's mentioned in the Torah. But where?

The significance of tsniut is already emphasized at the very beginning of the Torah. After Adam and Chava ate from the tree of knowledge and realized they were not dressed, they sewed clothes for themselves from fig leaves, as stated: "Then the eyes of both of them were opened, and they knew that they were not dressed; and they sewed fig leaves together and made themselves girdles."

Hashem also ensured that they were properly dressed, as the pasuk says: "And Hashem made for Adam and for his wife garments of skins and clothed them."

Also, our matriarchs taught us much about tsniut. Sarah Imenu was often in the tent, as emphasized by the angels when they inquired of Avraham Avinu about his wife's whereabouts, expressing approval that she was in the tent. Similarly, when Rivka saw Yitzchak, she immediately covered herself with a veil.

Halacha (בית יוסף והרמ"א ביורה דעה סימן קעח,א) derives the concept of tzniut from the verse "ובחוקותיהם לא תלכו" (and you shall not follow their statutes). The Shulchan Aruch specifies that one who behaves immodestly violates this prohibition.