LEV739 While Rashi states that these are commandments without logical reason, Nachmanides disagrees. He believes that God is telling man that there are limits to his ability and mandate to create and tamper with God's creation. Man may not make hybrids of plants and animals, because that kind of creation is beyond man's scope. Man can create in the world, but not create new species or new creations. Ibn Ezra also states that this prohibition limits man's ability to mix species in his creation (Nachmanides and Ibn Ezra commentaries on this verse]. These opinions seem to prohibit man's ability to manipulate genes or to even attempt cloning human beings, as this should remain in God's realm, not man's. Rabbi Samson Raphael Hirsch also indicates that God wishes to limit man's ability to create through the prohibition of Shatnez, mixing wool and linen. He says that will represents the kingdom of animals (the source of wool) while linen represents the kingdom of plants (the source of linen) [Hirsch commentary on this verse]. Man may not mix them, in order to show symbolically that man may not interfere in the creation of any species or change of any creation by God. Thus, cloning would be a realm beyond man's mandate to create in the world.