Matthew Poole and continuators on 1 Kings 7:21

21 And he set up the pillars in the porch of the temple : and he set up the right pillar, and called the name thereof Jachin : and he set up the left pillar, and called the name thereof Boaz.

Where they were placed for meer Ornament and Magnificence, for they supported nothing.

Iachin signifies he, i. e. God shall establish, to wit, his Temple, and Church, and People: and Boaz signifies, in it, or rather, in him (to answer the he in the former name) is strength. So these Pillars being eminently strong and stable, were in a manner Types or Documents of that strength which was in God, and▪ would be put forth by God for the defending and establishing of his Temple and People, if they were careful to keep the conditions required by God on their parts.

Marginal references: 2 Chr. 3▪ 17.; That is, he shall establish; That is, in it is strength.