Augustine of Hippo

Samuel bore with the wicked sons of Eli, his debased sons whom the people would not bear and who were thereupon accused by divine truth or disciplined by divine wrath; finally he bore with the people themselves in their pride and rejection of God.… Let them read who wish, and who can, the heavenly language. They will find that all the saints have had to tolerate among their own people those who were recognized as servants and friends of God.

Letter 43 ↗

Gregory the Dialogist

3. Supply "were." For who else are the sons of Eli, if not the Israelites according to the flesh, who knew the Sacred Scripture published by the fathers, and yet did not know the one whom Scripture had promised? Whom indeed Truth itself rebukes in the Gospel, saying: "Abraham rejoiced to see my day; he saw it, and was glad" (John 8:56). And again: "If you believed Moses, you would certainly believe me also, for he wrote about me" (John 5:46). Therefore they did not know the Lord, who spurned the Redeemer coming in our flesh. …

Commentary on 1 Kings, Book 2, Chapter 2 ↗

Bede

Furthermore, the sons of Eli, sons of Belial, etc. The sons of the Jewish priesthood, sons of blind light, or without a yoke (for both Belial and Beliar mean this), were those who did not know the doctrine of Christ; not following the commands of the divine law but adhering to their own statutes and traditions.

Commentary on Samuel ↗