Then he set up the pillars in front of the temple, one on the south and one on the north. The pillar on the south he named Jachin, and the pillar on the north he named Boaz.
Here is an account of 1. The two cherubim, which were set up in the holy of holies. There were two already over the ark, which covered the mercy-seat with their wings; these were small ones. Now that the most holy place was enlarged, though these were continued (being appurtenances to the ark, which was not to be made new, as all the other utensils...
Commenting on 2 Chronicles 3:10-17
He reared up the pillars - "The name of that on the right hand was Jachin, because the kingdom of the house of David was established; and the name of the left was Boaz, from the name of Boaz the patriarch of the family of Judah, from whom all the kings of the house of Judah have descended." - Targum.
2Ch 3:17 As to the position of the pillars, and their names, see on 1Ki 7:21.