This verse uses some unfamiliar terms. The words, "asp" and "cockatrice", mean a poisonous snake. Nothing could be more terrifying for a parent than to find their child playing around the den of poisonous serpents. In the Millennium, it won't matter for the sting of the serpent is gone. When Satan is bound for 1000 years, his earthly symbol, the serpent, will no longer strike. For they shall not hurt nor destroy in all my holy mountain (v. 9).