Inner Space Excerpted and adapted from a shiur by HaRav Chaim Weg January 13, 2022…
Beyond a Shadow
Rav Aryeh Finkel
July 29, 2021
Q We often picnic in a nearby park. On sunny days, it can be hard to find an available picnic table in a shady spot. There is an area at the park’s edge that is shaded by a church and stays cool. May we sit there and derive benefit from the church building, or must we sit in the hot sun instead?
A The Rambam rules that Christianity is avodah zarah (Hilchos Avodah Zarah 9:4). It is forbidden to derive benefit from avodah zarah and all its accessories, as the Torah says, “You shall not desire the gold and silver with [idols]” (Devarim 7:25). This tells us that anything used for idol worship is asur behana’ah, and that includes the building that houses it (Shulchan Aruch Y.D. 145:3).
Not only are tangible benefits prohibited, but even intangible ones like enjoying shade, as the Mishnah states that one may not sit under the shade of an Asheirah tree (Avodah Zarah 48b).
But the poskim debate whether the outdoor shade of a building wall is like that of a tree. The Ra’avad distinguishes between them, arguing that a tree (like the roof of a building) has the primary function of protecting the area beneath it, so in the case of avodah zarah, its shade is forbidden; but the walls of a building are primarily made to protect the area within them, so utilizing their shade outdoors is not considered having hana’ah from them.
However, many poskim do not differentiate between trees and buildings (see Shulchan Aruch Y.D. 142:10), so you must avoid benefiting from the shade cast by a church.
However, this applies only if there are no other seating areas available, even sunny ones. In the event that you can’t find any picnic area at all other than the spot shaded by the church, you may picnic there, provided you don’t deliberately intend to derive pleasure from the shade. (Shulchan Aruch ibid. 9; see also Taz ibid. 14.)
Note that picnicking directly on the church’s property in its shade (even with permission) is forbidden, even if no other spot is available (see Shach ibid. 20).