Awake
`uwr (oor)
to wake -- (a-)wake(-n, up), lift up (self), master, raise (up), stir up (self).
why sleepest
yashen (yaw-shane')
to be slack or languid, i.e. (by implication) sleep (figuratively, to die); also to grow old, stale or inveterate -- old (store), remain long, (make to) sleep.
thou O Lord
'Adonay (ad-o-noy')
the Lord (used as a proper name of God only) -- (my) Lord.
arise
quwts (koots)
to awake -- arise, (be) (a-)wake, watch.
cast us not off
zanach (zaw-nakh')
cast away (off), remove far away (off).
for ever
netsach (neh'-tsakh)
a goal, i.e. the bright object at a distance travelled towards; hence (figuratively), splendor, or (subjectively) truthfulness, or (objectively) confidence; but usually (adverbially), continually (i.e. to the most distant point of view)