Verses with the word stedfast in the Old Testament (4 verses):

Job 11:15
For then shalt thou lift up thy face without spot; yea, thou shalt be stedfast, and shalt not fear:

Psalms 78:8
And might not be as their fathers, a stubborn and rebellious generation; a generation that set not their heart aright, and whose spirit was not stedfast with God.

Psalms 78:37
For their heart was not right with him, neither were they stedfast in his covenant.

Daniel 6:26
I make a decree, That in every dominion of my kingdom men tremble and fear before the God of Daniel: for he is the living God, and stedfast for ever, and his kingdom that which shall not be destroyed, and his dominion shall be even unto the end.