Let thy priests
kohen (ko-hane')
literally, one officiating, a priest; also (by courtesy) an acting priest (although a layman) -- chief ruler, own, priest, prince, principal officer.
be clothed
labash (law-bash')
wrap around, i.e. (by implication) to put on a garment or clothe (oneself, or another), literally or figuratively
with righteousness
tsedeq (tseh'-dek)
the right (natural, moral or legal); also (abstractly) equity or (figuratively) prosperity -- even, (that which is altogether) just(-ice), (un-)right(-eous) (cause, -ly, -ness).
and let thy saints
chaciyd (khaw-seed')
kind, i.e. (religiously) pious (a saint) -- godly (man), good, holy (one), merciful, saint, (un-)godly.
shout for joy
ranan (raw-nan')
to creak (or emit a stridulous sound), i.e. to shout (usually for joy)