Malik related to me from Yahya ibn Said that Isa ibn Maryamencountered a pig on the road. He said to it, "Go in peace." Somebodyasked, "Do you say this to a pig?" Isa said, "I fear lest I accustommy tongue to evil speech."
USC-MSA web (English) reference: Book 56, Hadith 4
Arabic reference: Book 56, Hadith 1817