1)
Which north gate is this?
1.
Vilna Gaon: It is the north gate if Chatzer ha'Penimi.
2)
Why does it not say va'Yvi'eini El Chatzer ha'Penimi, like it says above (verse 32)?
1.
Malbim: Now he did not leave Chatzer ha'Penimi. He only went from the east to the north inside and first measured inside, and afterwards he left.