Verses with the word mast in the Old Testament (2 verses):

Proverbs 23:34
Yea, thou shalt be as he that lieth down in the midst of the sea, or as he that lieth upon the top of a mast.

Isaiah 33:23
Thy tacklings are loosed; they could not well strengthen their mast, they could not spread the sail: then is the prey of a great spoil divided; the lame take the prey.