Wisdom has built her house, she has hewn out her seven pillars:
All Commentaries on Proverbs 9:1 Go To Proverbs 9
Gregory The Dialogist
We may also not inappropriately interpret the “pillars of heaven” as the churches themselves. Being many in number, they constitute one catholic church spread over the whole face of the earth. So, too, the apostle John writes to the seven churches, meaning to denote the one catholic church replenished with the Spirit of sevenfold grace, and we know that Solomon said of the Lord, “Wisdom has built her a house; she has hewn out her seven pillars.” And to make known that it was of the seven churches he had spoken, which sedulously introduced the very sacraments themselves also, he says, “She has killed her sacrifices, she has mingled her wine, she has also set forth her table.” .