Avodah Zarah, Chapter 4, Mishnah 3. Our Mishnah deals with things that are connected to avodah zarah and identified with it, yet they do not serve it, glorify it or adorn it directly, nor are they among its accessories. The examples the Mishnah takes are a garden or a bathhouse located in the general vicinity of the avodah zarah and its temple, which do not stand there for the sake of its service or its glorification, but are part of the extended property of the avodah zarah and its temple. Under certain circumstances, benefiting from them is permitted.
The text of the Mishnah:
"Avodah zarah shehayah lah ginah o merchatz - nehenin mehen shelo b'tovah, v'ein nehenin mehen b'tovah" - an avodah zarah that has a garden or a bathhouse attached to its grounds: one may benefit from them when no 'tovah' (favor) is given, and one may not benefit from them when 'tovah' is given.
What is this 'tovah'?
The view of most Rishonim: 'tovah' means money. When a person pays a sum to enter the bathhouse connected to the temple of the avodah zarah, his money benefits the priest who serves the idol, and he thereby supports the worship of the idol itself - and therefore it is completely forbidden. But if he enters free of charge, benefiting from it is permitted.
The view of Rabbeinu Tam: 'tovah' includes even merely expressing thanks to the owner, that is, to the priest, and that too is forbidden.
The halachah takes both of these views into account.
A garden and a bathhouse under joint ownership:
"Hayah shelo v'shel acherim - nehenin mehen bein b'tovah u'vein shelo b'tovah" - if the bathhouse or the garden connected to the house of avodah zarah are under the joint ownership of the priests of the temple together with others who are not idol worshippers, and even a Jew, one may benefit from them whether with tovah or without tovah.
According to the approach that tovah means a monetary payment, the Gemara explains that the sum of money paid is less than the ordinary price of general admission to a public bathhouse elsewhere. It turns out that there is no real benefit from the avodah zarah here, but rather a bargain that the person gains in its own right. Furthermore, the money does not benefit the priest, since it goes to the other partner who is not an idol worshipper, and therefore this is not forbidden benefit.