Psalms 91:13

Thou shalt tread upon the lion and adder,.... Or be unhurt by such savage and poisonous creatures; as the Israelites, when they travelled through the wilderness, in which were serpents and scorpions; and many of the servants of God have been delivered from them, or have slain them, as Samson, David, and Daniel; and so Christ was among the wild beasts in the wilderness, and yet not touched or hurt by them; and his disciples had power given them by him to tread on serpents and scorpions, and to take up serpents, without receiving any damage from them; and when a viper fastened on the hand of the Apostle Paul, he shook it off, without being hurt by it; see Mark 1:13

Acts 28:5, it may be understood figuratively of Satan, who, for his voraciousness and cruelty, is compared to a lion; and, for his craft and subtlety, to a serpent, 1 Peter 5:8,

the young lion and the dragon shalt thou trample underfoot; which also may be understood of the great dragon, the old serpent, called the devil and Satan; whom Christ trampled under his feet when he hung on the cross, and spoiled him and his principalities and powers; and who, in a short time, will be bruised under the feet of his people, as he has been already by the seed of the woman, Genesis 3:15.