Serve
`abad (aw-bad')
to work (in any sense); by implication, to serve, till, (causatively) enslave, etc.
the LORD
Yhovah (yeh-ho-vaw')
(the) self-Existent or Eternal; Jehovah, Jewish national name of God -- Jehovah, the Lord.
with gladness
simchah (sim-khaw')
blithesomeness or glee, (religious or festival) -- exceeding(-ly), gladness, joy(-fulness), mirth, pleasure, rejoice(-ing).
come
bow' (bo)
to go or come (in a wide variety of applications)
before his presence
paniym (paw-neem')
the face (as the part that turns); used in a great variety of applications (literally and figuratively); also (with prepositional prefix) as a preposition (before, etc.)
with singing
rnanah (ren-aw-naw')
a shout (for joy) -- joyful (voice), singing, triumphing.