Girded with a linen ephod - This was the usual dress of the priests. It does not appear whether Levites wore an ephod properly. Possibly it was a mark of Samuel's special dedication to the Lord's service that he wore one. (See the marginal reference). The ephod was sometimes used as an idolatrous implement Judges 8:27.

Girded with a linen ephod - This the Targum translates אסיר כרדוט דבוץ asir cardut debuts, "Girded with a cardit of byssus, or fine linen." The word cardut they seem to have borrowed from the Greek χειριδωτος, a tunic, having χειριδας, i.e., sleeves that came down to, or covered, the hands. This was esteemed an effeminate garment among the Romans. See Buxtorf's Talmudic Lexicon.

But Samuel ministered before the Lord,.... The ministration of Samuel, though a child, is observed both before and after the account of the ill behaviour and wickedness of Eli's sons; partly to the shame and disgrace of them, and as serving to aggravate their sin, and make it appear the more black and heinous; and partly to his honour and reputation, that he was not corrupted and turned aside from God by their evil practices. The phrase here used is different from that in 1-Samuel 2:11 there he is said to minister before Eli, under his direction and guidance, but here before the Lord; being now engaged in higher services, and which he could perform without the assistance of Eli, as in the presence of God more immediately; it seems to have respect to him when more grown in age, stature, knowledge, and experience, though here related: yet still being "a child"; not got out of his childhood, or arrived to manhood:
girded with a linen ephod; such as priests used to wear, but not Levites in common, nor extraordinary persons on extraordinary occasions, see 1-Samuel 22:18. This seems to be a peculiar favour, and a special honour which Eli granted to Samuel when so very young, on account of the grace of God bestowed on him in a wonderful manner; and because brought up in the tabernacle as a holy person, and a Nazarite; and because his birth was foretold, and he asked of God, as his name signified, as Procopius Gazaeus observes.

SAMUEL'S MINISTRY. (1-Samuel 2:18-26)
But Samuel ministered before the Lord, being a child--This notice of his early services in the outer courts of the tabernacle was made to pave the way for the remarkable prophecy regarding the high priest's family.
girded with a linen ephod--A small shoulder-garment or apron, used in the sacred service by the inferior priests and Levites; sometimes also by judges or eminent persons, and hence allowed to Samuel, who, though not a Levite, was devoted to God from his birth.

Samuel's service before the Lord. - 1-Samuel 2:18. Samuel served as a boy before the Lord by the side of the worthless sons of Eli, girt with an ephod of white material (בּד, see at Exodus 28:42). The ephod was a shoulder-dress, no doubt resembling the high priest's in shape (see Exodus 28:6.), but altogether different in the material of which it was made, viz., simple white cloth, like the other articles of clothing that were worn by the priests. At that time, according to 1-Samuel 22:18, all the priests wore clothing of this kind; and, according to 2-Samuel 6:14, David did the same on the occasion of a religious festival. Samuel received a dress of this kind even when a boy, because he was set apart to a lifelong service before the Lord. חגוּר is the technical expression for putting on the ephod, because the two pieces of which it was composed were girt round the body with a girdle.

Ministered - That is, performed his ministration carefully and faithfully. Before the Lord - In God's tabernacle. Ephod - A garment used in God's service, and allowed not only to the inferior priests and Levites but also to eminent persons of the people, and therefore to Samuel, who, though no Levite, was a Nazarite, from his birth.