Avodah Zarah 62 - Loophole for Working with Libation Wine

If an idol worshipper hires a Jewish worker to do work for him in handling libation wine, either to pour it into barrels or to transport the barrels, the worker's wage is prohibited for benefit. However, if he hired the worker to do other work for him, then even if he said to him, "Transport this barrel of libation wine from one place to another," the worker's wage is permitted.

If an idol worshipper hires a Jew's donkey to transport libation wine on it, the rental fee is prohibited for benefit. However, if he hired the donkey to ride on, then even if the idol worshipper later placed his flask of wine on it, the fee is permitted.

Both laws are a stringency that the Sages enacted against the continued existence of idol worship.

Art: Donkeys in a Glade by Edward Robert Smythe