פירוש על עבודה זרה 129:11

The Talmud turns to another aspect of this arrangement. If one hires a donkey driver to transport him somewhere, what may he bring without specifying and what can the donkey driver bring. The hirer may bring his clothes, a jar with drink and food sufficient for the whole journey. The donkey-driver can bring food for his donkey and his own food but only enough for the day. From here we can see that when one hires a donkey, it can be assumed that he is bringing his wine. Carrying the wine is part of the deal. Therefore, it would seem that the Jew is being paid for transporting wine. But the mishnah assumes that the Jew is not being paid for this. He is only being paid for carrying the non-Jew and therefore it is permitted.