Thou shalt tread upon the lion and adder: the young lion and the dragon shalt thou trample under feet. Thou shalt tread upon the lion and adder - Even the king of the forest shall not be able to injure thee; should one of these attack thee, the angels whom God sends will give thee an easy victory over him. And even the asp, (פתן pethen), one of the most venomous of serpents, shall not be able to injure thee.
The asp is a very small serpent, and peculiar to Egypt and Libya. Its poison kills without the possibility of a remedy. Those who are bitten by it die in about from three to eight hours; and it is said they die by sleep, without any kind of pain. Lord Bacon says the asp is less painful than all the other instruments of death. He supposes it to have an affinity to opium, but to be less disagreeable in its operation. It was probably an this account that Cleopatra, queen of Egypt, chose to die by the asp, as she was determined to prevent the designs of Augustus, who intended to have carried her captive to Rome to grace his triumph.
The dragon shalt thou trample - The תנין tannin, which we translate dragon, means often any large aquatic animal; and perhaps here the crocodile or alligator.