וְכֹ֣ל ׀ הוֹלֵ֣ךְ עַל־כַּפָּ֗יו בְּכָל־הַֽחַיָּה֙ הַהֹלֶ֣כֶת עַל־אַרְבַּ֔ע טְמֵאִ֥ים הֵ֖ם לָכֶ֑ם כָּל־הַנֹּגֵ֥עַ בְּנִבְלָתָ֖ם יִטְמָ֥א עַד־הָעָֽרֶב׃
And whatsoever goeth upon its paws, among all beasts that go on all fours, they are unclean unto you; whoso toucheth their carcass shall be unclean until the even.
Read kabbalistic (mystical) interpretation of Leviticus 11:27: and classical mystical sources.