Nehemiah 2

Nehemiah 2:16

The officials did not know where I had gone or what I had done; nor had I as yet told the Jews, the priests, the nobles, the officials or the rest who did the work.

Nehemiah is playing things close to the chest here.  He's gone out, in the dark of night, to inspect the walls.  He has told no one what he's up to, though apparently they knew he had gone somewhere.  But why did he do it so secretly?  I have two theories.

First, he was doing it at a time when the opposition would not be aware.  This is a city that is barely inhabited.  Probably has few to no watchmen, so there was likely nobody there to see him checking things out.  The upside of this is that those who would come to oppose the work were not aware he was starting the process.  Before the work can begin, it would have to be surveyed, to determine what work was needed, and what time and materials would be required.

Second, he was clearing the way for the people to begin.  He hadn't told the people he was there to rebuild the wall, and he was doing all the preparatory work he could, to minimize any issues that might arise.  This also allowed him to minimize the complaints from any workers, since he's done everything except the actual building.  He has the approvals and the plans; all he needs now is the workers to actually start.