Sefer Chasidim Siman 437
Can copy this into an AI, or connect the whole library to your assistant. For deeper learning, you can directly use the original seforim, sites, and apps.
אם אדם בבית הכנסת וראה דרך חלון בית ע"ז או שתי וערב ישים בחלון שום דבר כדי שלא יראנו:
Medieval Jewish mysticism, translated by Sholom Alchanan Singer. Northbrook, Ill. Whitehall Co., 1971
If a person was in a synagogue and saw through a window a house of idolatry or an idol or a graven image - he should place something in the window in order to block their view.