Albert Barnes Commentary 1 Samuel 1:3

"And this man went up out of his city from year to year to worship and to sacrifice unto Jehovah of hosts in Shiloh. And the two sons of Eli, Hophni and Phinehas, priests unto Jehovah, were there." — 1 Samuel 1:3 (ASV)

During the unsettled times of the Judges (Judges 21:25), it is likely that the Israelites' attendance at the three required festivals fell into disuse or became very irregular (Exodus 34:23; Deuteronomy 16:16). This one particular feast, which may have coincided with the Feast of Pentecost or Tabernacles, might have been substituted for them.

The Lord of Hosts - This title for Yahweh, which is found with some variations more than 260 times in the Old Testament, occurs here for the first time. The meaning of the word “hosts” is undoubtedly the same as that of “army” (Daniel 4:35) and includes all the myriads of holy angels who inhabit the heavens (1 Kings 22:19). It is probable that the title “Lord of Hosts” was given to the true God with reference to the idolatrous worship of the “host of heaven,” thereby asserting His universal supremacy . In the New Testament, the phrase occurs only once (James 5:4).

And the two sons... - The text should be read as, “and there the two sons of Eli, Hophni and Phinehas, were priests to the Lord.” This means they were performing the functions of priests during the old age of Eli (1 Samuel 4:18), who is described in 1 Samuel 1:9 as sitting on a seat in the temple. The reading of the Greek Version—“Eli was there, and his two sons, Hophni and Phinehas, priests of the Lord”—is unnecessary and, in fact, destroys the meaning. The information given here concerning Eli’s sons is followed up in 1 Samuel 2:12 and following.