Albert Barnes Commentary Nehemiah 2:18

"And I told them of the hand of my God which was good upon me, as also of the king`s words that he had spoken unto me. And they said, Let us rise up and build. So they strengthened their hands for the good [work]." — Nehemiah 2:18 (ASV)

The king’s words - These have not been given; but the royal permission to restore the walls is implied in Nehemiah 2:5-6.