In that day
yowm (yome)
a day (as the warm hours),
shall Israel
Yisra'el (yis-raw-ale')
he will rule as God; Jisrael, a symbolical name of Jacob; also (typically) of his posterity: --Israel.
be the third
shliyshiy (shel-ee-shee')
third; feminine a third (part); by extension, a third (day, year or time); specifically, a third-story cell) -- third (part, rank, time), three (years old).
with Egypt
Mitsrayim (mits-rah'-yim)
Mitsrajim, i.e. Upper and Lower Egypt -- Egypt, Egyptians, Mizraim.
and with Assyria
'Ashshuwr (ash-shoor')
Ashshur, the second son of Shem; also his descendants and the country occupied by them (i.e. Assyria), its region and its empire
even a blessing
Brakah (ber-aw-kaw')
benediction; by implication prosperity -- blessing, liberal, pool, present.
in the midst
qereb (keh'-reb)
the nearest part, i.e. the center, whether literal, figurative or adverbial (especially with preposition)
of the land
'erets (eh'-rets)
the earth (at large, or partitively a land) -- common, country, earth, field, ground, land, natins, way, + wilderness, world.