To him that smote
nakah (naw-kaw')
to strike (lightly or severely, literally or figuratively)
Egypt
Mitsrayim (mits-rah'-yim)
Mitsrajim, i.e. Upper and Lower Egypt -- Egypt, Egyptians, Mizraim.
in their firstborn
bkowr (bek-ore')
firstborn; hence, chief -- eldest (son), firstborn(-ling).
for his mercy
checed (kheh'-sed)
kindness; by implication (towards God) piety: rarely (by opposition) reproof, or (subject.) beauty
endureth for ever
`owlam (o-lawm')
concealed, i.e. the vanishing point; generally, time out of mind (past or future), i.e. (practically) eternity; frequentatively, adverbial (especially with prepositional prefix) always
