For all the firstborn
bkowr  (bek-ore')
firstborn; hence, chief -- eldest (son), firstborn(-ling).
of the children
ben  (bane)
a son (as a builder of the family name), in the widest sense (of literal and figurative relationship, including grandson, subject, nation, quality or condition, etc.
of Israel
Yisra'el  (yis-raw-ale')
he will rule as God; Jisrael, a symbolical name of Jacob; also (typically) of his posterity: --Israel.
are mine both man
'adam  (aw-dawm')
ruddy i.e. a human being (an individual or the species, mankind, etc.) -- another, + hypocrite, + common sort, low, man (mean, of low degree), person.
and beast
bhemah  (be-hay-maw')
a dumb beast; especially any large quadruped or animal (often collective) -- beast, cattle.
on the day
yowm  (yome)
a day (as the warm hours),
that I smote
nakah  (naw-kaw')
to strike (lightly or severely, literally or figuratively)
every firstborn
bkowr  (bek-ore')
firstborn; hence, chief -- eldest (son), firstborn(-ling).
in the land
'erets  (eh'-rets)
the earth (at large, or partitively a land) -- common, country, earth, field, ground, land, natins, way, + wilderness, world.
of Egypt
Mitsrayim  (mits-rah'-yim)
Mitsrajim, i.e. Upper and Lower Egypt -- Egypt, Egyptians, Mizraim.
I sanctified
qadash  (kaw-dash')
to be (causatively, make, pronounce or observe as) clean (ceremonially or morally)
them for myself