words - Wording in Torah when Moshe is commanded to appear before Pharaoh

This shabbos, the Parasha, Bo, starts with Moshe being told to "Bo El Paroh", "Come to Pharaoh". I don't understand this wording, should it have said "Lech El Paroh", "go to Pharaoh"? Is there a reason why the command was worded that way?