This verse tells us at least two things. First, it gives us the practical result of Solomon’s judicial sentence on Abiathar. Second, it shows us the divine perspective from which we should regard it.
Practically speaking, it expelled Abiathar from the office of his priesthood. When he was confined to his estate it meant that he had no access to the tabernacle (or later the temple, if he survived that long). Without such access, he was unable to exercise the chief function of the priesthood. It excluded him from the altars and from the service of the Day of Atonement (assuming that he had previously been the high priest). In our times it would be somewhat similar to an ordained minister of the Word and sacraments being deposed from the ministry. It was a humiliating punishment.
From the divine perspective we are told that it fulfilled God’s prophecy that the priesthood would be removed from the family of Eli. This was a prophecy that had been given to Samuel when he was still a small child (1 Samuel 3:11–14). Given that Samuel was an old man when Saul was anointed king and that David had reigned forty years subsequent to Saul’s death, well over a century must have passed since the prophecy was given.
Regarding this, we might well make use of the saying, The mills of God grind slowly, but they grind exceedingly small.
It is well that we should be reminded that the Lord may delay in the execution of his will, but his counsel always stands (Isaiah 46:10; Proverbs 19:21).
27 So Solomon expelled Abiathar from being priest to the LORD, thus fulfilling the word of the LORD that he had spoken concerning the house of Eli in Shiloh.