Verses with the word slumber in the Old Testament (9 verses):

Psalms 121:3
He will not suffer thy foot to be moved: he that keepeth thee will not slumber.

Psalms 121:4
Behold, he that keepeth Israel shall neither slumber nor sleep.

Psalms 132:4
I will not give sleep to mine eyes, or slumber to mine eyelids,

Proverbs 6:4
Give not sleep to thine eyes, nor slumber to thine eyelids.

Proverbs 6:10
Yet a little sleep, a little slumber, a little folding of the hands to sleep:

Proverbs 24:33
Yet a little sleep, a little slumber, a little folding of the hands to sleep:

Isaiah 5:27
None shall be weary nor stumble among them; none shall slumber nor sleep; neither shall the girdle of their loins be loosed, nor the latchet of their shoes be broken:

Isaiah 56:10
His watchmen are blind: they are all ignorant, they are all dumb dogs, they cannot bark; sleeping, lying down, loving to slumber.

Nahum 3:18
Thy shepherds slumber, O king of Assyria: thy nobles shall dwell in the dust: thy people is scattered upon the mountains, and no man gathereth them.