1)
Why did they take the shields and return them?
1.
'Rashi' citing his Rebbi: It is because Rechav'am feared Melech Mitzrayim and Melech Yisrael.
2.
Malbim (10-11): They were not needed; they were take when he went to pray in Beis Hashem. There is no danger then! Rather, it was to [remind him that the gold shields were taken due to his sin, and] humble him.
2)
What is "Ta ha'Ratzim"?
