Numbers 27:23 And he laid his hands upon him, and gave him a charge, as the LORD commanded by the hand of Moses.
When God was ready to move the leadership from Moses to Joshua, He instructed Moses to lay hands on Joshua. As he laid hands on Joshua, he was also to give him a charge. It was a symbol of transferring power and authority. Moses charged Joshua to honor God and lead the people as God would direct.
This is where we see what we do in our special services of ordination. We recognize that God has called someone to His service. We are challenging that person to honor God and lead as pleases the Lord. We are showing the people that we believe in that person and that we realize that God is calling him to this work.