{And over all the power of the enemy} (kai epi p(8373)an t(886e)
dunamin tou echthrou). This is the heart of "the authority"
(	(886e) exousian) here given by Jesus which is far beyond their
expectations. The victory over demons was one phase of it. The
power to tread upon serpents is repeated in  Mr 16:18  (the
Appendix) and exemplified in Paul's case in Malta ( Ac 28:3-5 ).
But protection from physical harm is not the main point in this
struggle with Satan "the enemy" ( Mt 13:25  Ro 16:20  1Pe 5:8 ).
{Nothing shall in any wise hurt you} (ouden hum(8373) ou m(880a)adik(8873)ei). Text has future active indicative, while some MSS.
read adik(8873)(8869), aorist active subjunctive of adike(935c), common
verb from adikos (a privative and dikos), to suffer wrong,
to do wrong. The triple negative here is very strong. Certainly
Jesus does not mean this promise to create presumption or
foolhardiness for he repelled the enemy's suggestion on the
pinnacle of the temple.