24 And the people said to Joshua, “We will serve the LORD our God and obey him.” 25 On that day Joshua made a covenant for the people, and there at Shechem he reaffirmed for them decrees and laws. 26 And Joshua recorded these things in the Book of the Law of God. Then he took a large stone and set it up there under the oak near the holy place of the LORD. 27 “See!” he said to all the people. “This stone will be a witness against us. It has heard all the words the LORD has said to us. It will be a witness against you if you are untrue to your God.” 28 Then Joshua dismissed the people, each to their own inheritance.
Notice that the stone has "heard" all the words the Lord had said. You've heard the phrase "if these walls could speak..." My mind started wondering, Jesus speaks about the rocks crying out. What if rocks could cry out, what would they say?
All this is simply a reminder to me that nothing is hidden from the Lord.