'Firm' in the Bible

And while all [the people of] Israel crossed over on dry ground, the priests who carried the ark of the covenant of the Lord stood firm on dry ground in the midst of the Jordan [riverbed], until all the nation had finished crossing over the Jordan.

and command them, ‘Pick up for yourselves twelve stones [one each] from here out of the midst of the Jordan, from the place where the priests’ feet are standing firm; carry them over with you and lay them down at the place where you will spend the night tonight.’”