So the realm
malkuwth  (mal-kooth')
a rule; concretely, a dominion -- empire, kingdom, realm, reign, royal.
of Jehoshaphat
Yhowshaphat  (yeh-ho-shaw-fawt')
Jehovah-judged; Jehoshaphat, the name of six Israelites; also of a valley near Jerusalem -- Jehoshaphat.
was quiet
shaqat  (shaw-kat')
to repose (usually figurative) -- appease, idleness, (at, be at, be in, give) quiet(-ness), (be at, be in, give, have, take) rest, settle, be still.
for his God
'elohiym  (el-o-heem')
angels, exceeding, God (gods)(-dess, -ly), (very) great, judges, mighty.
gave him rest
nuwach  (noo'-akh)
to rest, i.e. settle down; used in a great variety of applications
round about
cabiyb  (saw-beeb')
(as noun) a circle, neighbour, or environs; but chiefly (as adverb, with or without preposition) around -- (place, round) about, circuit, compass, on every side.