משנה על ויקרא 19:19

A wolf and a dog, a wild dog and a fox, a goat and a deer, a gazelle and a ewe-lamb, a horse and a mule, or a mule and a donkey, a donkey and a wild donkey, even though they are similar one to the other, constitute nevertheless, kilayim one with the other.

The baskets of a pack-saddle, the bed of a barrow, the iron corner of a bier, the [drinking] horns of travelers, a key chain, the loose stitches of washermen, and a garment stitched together with kilayim are regarded as connected in respect of uncleanness but not in that of sprinkling.