Reference for Avodah Zarah 118:1

ובדודורין אע"פ שהיין מזלף עליהן מותר א"ל הביא קאמרת אנא לכתחלה קאמינא

or barrels, even though the wine drips upon them, they are permitted! [R. Kahana] replied to him: You used the word “carried,” I was speaking of a case of ab initio.

Jastrow