Let Israel
Yisra'el (yis-raw-ale')
he will rule as God; Jisrael, a symbolical name of Jacob; also (typically) of his posterity: --Israel.
rejoice
samach (saw-makh')
probably to brighten up, i.e. (figuratively) be (causatively, make) blithe or gleesome
in him that made
`asah (aw-saw')
to do or make, in the broadest sense and widest application
him let 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 Zion
Tsiyown (tsee-yone')
Tsijon (as a permanent capital), a mountain of Jerusalem -- Zion.
be joyful
giyl (gheel)
to spin round (under the influence of any violent emotion), i.e. usually rejoice, or (as cringing) fear -- be glad, joy, be joyful, rejoice.
in their King
melek (meh'-lek)
a king -- king, royal.