1)
Why did he need to say "u'Vasa Shamah"?
1.
Malbim #1: If you go quickly, you will find Yehu with the other officers.
2.
Malbim #2: Since the Navi did not recognize Yehu, he commanded him that when he comes, he should see him in the city to recognize him, and later he will come to when he is amidst his brothers and take him from among them, and then take him to an inner room. This was lest the king find out.
2)
What is the meaning of "Cheder b'Chader"?
1.
Radak: It is an inner room.
