Verses with the word firm in the Old Testament (6 verses):

Joshua 3:17
And the priests that bare the ark of the covenant of the LORD stood firm on dry ground in the midst of Jordan, and all the Israelites passed over on dry ground, until all the people were passed clean over Jordan.

Joshua 4:3
And command ye them, saying, Take you hence out of the midst of Jordan, out of the place where the priests' feet stood firm, twelve stones, and ye shall carry them over with you, and leave them in the lodging place, where ye shall lodge this night.

Job 41:23
The flakes of his flesh are joined together: they are firm in themselves; they cannot be moved.

Job 41:24
His heart is as firm as a stone; yea, as hard as a piece of the nether millstone.

Psalms 73:4
For there are no bands in their death: but their strength is firm.

Daniel 6:7
All the presidents of the kingdom, the governors, and the princes, the counsellors, and the captains, have consulted together to establish a royal statute, and to make a firm decree, that whosoever shall ask a petition of any God or man for thirty days, save of thee, O king, he shall be cast into the den of lions.