Verse 4: And when the time was that Elkanah (Deut. 12:17, 18; 16:11) offered, he gave to Peninnah his wife, and to all her sons and her daughters, portions…
[Now, a day came] Hebrew: and it was the day (Montanus, Septuagint, Jonathan), namely, of the solemnity, or a solemn day (Jonathan, Munster, Kimchi in Drusius), or, a feast day (Tigurinus). Now, when the day had come, that is, on which Elkanah was wont to sacrifice (Vatablus).
[And he sacrificed] Namely, by the Priests (Malvenda, Mendoza). [See on verse 3.] He was unwilling to appear before the Lord empty, in accordance with Deuteronomy 16:16, 17 (Malvenda).
[And he gave to Peninnah, etc.] Therefore, this sacrifice was not a burnt-offering (because the burnt-offering was consecrated entirely to God), but a peace-offering, or a Thank-offering, a good part of which was falling back to the offerers. See Leviticus 3; 7; Deuteronomy 12; 16 (Sanchez, Menochius, Tirinus, similarly Mendoza, Lapide, Piscator, Drusius, Lyra). Hence we are informed that his entire family was present. His family is an illustrious example of piety. And so it is fitting that everyone instruct his own in the fear and law of God (Martyr, similarly Lapide). But why did he give first to Peninnah, etc.? Responses: 1. Perhaps so that he might conceal his love toward Hannah, and take away an occasion for dispute. 2. It is thus arranged, not because Elkanah gave first to Peninnah, but because the Writer is going to say more things concerning Hannah. See on Matthew 1:1; Revelation 1:4, 5 (Mendoza). But he was giving these portions for the sake of friendship and honor; thus the ancients were wont γεραίρειν, to honor, certain ones: Athenæus’ Banquet of the Learned 1. And κρεωδαισία or κρεωνομία, distribution of meats) was also used in other feasts, as it is evident out of Homer and Plutarch (Serarius). Those that were offering שְׁלָמִים/peace-offerings, their Priest, with his parts removed, was removing the rest, from which a feast was prepared: but the master of the feast was giving to his guests the portions that he would, as in Genesis 43:34 (Grotius).
Portions: To wit, out of the sacrifice of his peace-offerings, the greatest part whereof fell to the offerer, and was eaten by him and his friends or guests before the Lord, Leviticus 3; 7; Deuteronomy 12:12; 16:11; and out of this he gave them all parts or portions, as the master of the feast used to do to guests.