Date: 13 Iyar 5565
From: Rabbi Moshe Sofer
To: Unknown recipient
The Chasam Sofer defends the Taz's principle that the Sages cannot prohibit what the Torah explicitly permits, against challenges from the Chavos Yair (regarding interest from non-Jews) and from the laws of meat and milk. He argues that the Rabbinic prohibition on lending to non-Jews with interest targets a different prohibition (assimilation), not the interest permission itself, and that the Torah never explicitly permitted pickling or roasting meat in milk — it only prohibited cooking.
Source: Shu"t Chasam Sofer YD §109