This psalm purports also to be a psalm of Asaph. See Introduction to Ps. 73. In the absence of any evidence to the contrary, it may be assumed to have been composed by or for the Asaph who was the contemporary of David, and who was, appointed by him to preside over the music of the sanctuary. Venema, indeed, supposes that the psalm was composed in the time of Josiah, at the observance of the great Passover celebrated by him 2 Chr. 35; but there is no positive evidence of this, though there is nothing in the psalm that is inconsistent with such a supposition. On the phrase in the title, upon Gittith, see the notes at the title to Psalm 8:1-9.
The occasion on which the psalm was composed seems to have been a festal occasion, and the circumstances in the psalm will probably best accord with the supposition that it was the Feast of the Passover. Rosenmuller has indeed endeavored to show (see his notes at Psalm 81:4) that it was composed on occasion of the Feast of Trumpets (Leviticus 23:24, following); but there is nothing in the psalm which would necessarily restrict it to that, and, as we shall see, all the circumstances in the psalm harmonize with the supposition that it was at the Feast of the Passover, the principal and the most important festival of the Hebrews. It is well remarked by DeWette (Introduction to the psalm), that as the Hebrews were required to make known to their children the design of the ordinance of the Passover (see Exodus 12:26-27), nothing would be more natural than that the sacred poets should take occasion from the return of that festival to enforce the truths pertaining to it in songs composed for the celebration. Such seems to have been the design of this psalm - reminding the people of the goodness of God in the past, and recalling them from their sins by a remembrance of his mercies, and by a view of what would be the consequences of fully obeying his law.
It would seem from the psalm not improbable that it was composed in a time of national declension in religion, and when there was a tendency to idolatry, and that the object of the author was to rouse the nation from that state, and to endeavor by a reference to the past to bring them back to a more entire devotedness to God.
The contents of the psalm are as follows:
I. The duty of praise, particularly on such occasions as that on which the psalm was composed; a duty enjoined even in Egypt, in the time of Joseph, when God delivered his people out of that strange land, Psalm 81:1-7.
II. The main command which was then ordained to be the guide of the people - the fixed law of the nation - the fundamental idea in their polity - that there was to be no strange god among them, but that they were to worship the true God, and him alone, Psalm 81:8-10.
III. The fact that the nation had refused to hear; that there had been such a proneness to worship other gods, and to fall into the habits of idolaters, that God had given them up to their own desires, and suffered them to walk in their own ways, Psalm 81:11-12.
IV. A statement of what God would have done for them if they had been obedient; of what would have been the effect on their national prosperity if they had hearkened to the commands of God; and consequently of what would still be the result if the people should be obedient, and submit themselves wholly to the law of God, Psalm 81:13-16. Particularly:
(1) Their enemies would have been subdued, Psalm 81:14.
(2) those who hated the Lord would have yielded themselves to him, Psalm 81:15.
(3) God would have given them abundant prosperity; he would have fed them with the finest of the wheat, and would have satisfied them with honey out of the rock, Psalm 81:16.
The psalm is of special importance to the church now, as reminding it of its obligation from the past mercies of God, and as showing what would be the consequences if it should be wholly devoted to the service of God.

An exhortation to the people to praise God for his benefits, Psalm 81:1-7; and to attend to what he had prescribed, Psalm 81:8-10; their disobedience lamented, Psalm 81:11; the miseries brought on themselves by their transgressions, Psalm 81:12-16.
The title is the same as to Psalm 8:1-9 (note), which see. There are various opinions concerning the occasion and time of this Psalm: but it is pretty generally agreed that it was either written for or used at the celebration of the Feast of Trumpets, (see on Leviticus 23:24 (note)), which was held on the first day of the month Tisrl, which was the beginning of the Jewish year; and on that day it is still used in the Jewish worship. According to Jewish tradition, credited by many learned Christians, the world was created in Tisri, which answers to our September. The Psalm may have been used in celebrating the Feast of Trumpets on the first day of Tisri, the Feast of Tabernacles on the fifteenth of the same month, the creation of the world, the Feasts of the New Moons, and the deliverance of the Israelites from Egypt; to all which circumstances it appears to refer.

INTRODUCTION TO PSALM 81
To the chief Musician upon Gittith, A Psalm of Asaph. Of "gittith", See Gill on Psalm 8:1. The Targum renders it,
"upon the harp which came from Gath;''
and so Jarchi says it was a musical instrument that came from Gath. The Septuagint, and the versions which follow that, render it, "for the winepresses". This psalm, according to Kimchi, is said concerning the going out of the children of Israel from Egypt; and was composed in order to be sung at their new moons and solemn feasts, which were typical of Gospel things in Gospel times; see Colossians 2:16 and so the Syriac version,
"a psalm of Asaph, when David by him prepared himself for the solemnities.''.

(Psalm 81:1-7) God is praised for what he has done for his people.
(Psalm 81:8-16) Their obligations to him.

Easter Festival Salutation and Discourse
Ps 80, which looks back into the time of the leading forth out of Egypt, is followed by another with the very same Asaphic thoroughly characteristic feature of a retrospective glance at Israel's early history (cf. More particularly Psalm 81:11 with Psalm 80:9). In Psalm 81 the lyric element of Ps 77 is combined with the didactic element of Ps 78. The unity of these Psalm is indubitable. All three have towards the close the appearance of being fragmentary. Fro the author delights to ascend to the height of his subject and to go down into the depth of it, without returning to the point from which he started. In Ps 77 Israel as a whole was called "the sons of Jacob and Joseph;" in Ps 78 we read "the sons of Ephraim" instead of the whole nation; here it is briefly called "Joseph." This also indicates the one author. Then Psalm 81, exactly like Psalm 79:1-13, is based upon the Pentateuchal history in Exodus and Deuteronomy. Jahve Himself speaks through the mouth of the poet, as He did once through the mouth of Moses - Asaph is κατ ̓ ἐξοχήν the prophet (חזה) among the psalmists. The transition from one form of speech to another which accompanies the rapid alternation of feelings, what the Arabs call talwı̂n el-chitab, "a colouring of a speech by a change of the persons," is also characteristic of him, as later on of Micah (e.g., Micah 6:15.).
This Psalm 81 is according to ancient custom the Jewish New Year's Psalm, the Psalm of the Feast of Trumpets (Numbers 29:1), therefore the Psalm of the first (and second) of Tishri; it is, however, a question whether the blowing of the horn (shophar) at the new moon, which it calls upon them to do, does not rather apply to the first of Nisan, to the ecclesiastical New Year. In the weekly liturgy of the Temple it was the Psalm for the Thursday.
The poet calls upon them to give a jubilant welcome to the approaching festive season, and in Psalm 81:7. Jahve Himself makes Himself heard as the Preacher of the festival. He reminds those now living of His loving-kindness towards ancient Israel, and admonishes them not to incur the guilt of like unfaithfulness, in order that they may not lose the like tokens of His loving-kindness. What festive season is it? Either the Feast of the Passover or the Feast of Tabernacles; for it must be one of these two feasts which begin on the day of the full moon. Because it is one having reference to the redemption of Israel out of Egypt, the Targum, Talmud (more particularly Rosh ha-Shana, where this Psalm is much discussed), Midrash, and Sohar understand the Feast of Tabernacles; because Psalm 81:2-4 seem to refer to the new moon of the seventh month, which is celebrated before the other new moons (Numbers 10:10), as יום התּרוּעה (Numbers 29:1, cf. Leviticus 23:24), i.e., to the first of Tishri, the civil New Year; and the blowing of horns at the New Year, is, certainly not according to Scripture, but yet according to tradition (vid., Maimonides, Hilchoth Shophar Psalm 1:2), a very ancient arrangement. Nevertheless we must give up this reference of the Psalm to the first of Tishri and to the Feast of Tabernacles, which begins with the fifteenth of Tishri: - (1) Because between the high feast-day of the first of Tishri and the Feast of Tabernacles on the fifteenth to the twenty-first (twenty-second) of Tishri lies the great day of Atonement on the tenth of Tishri, which would be ignored, by greeting the festive season with a joyful noise from the first of Tishri forthwith to the fifteenth. (2) Because the remembrance of the redemption of Israel clings far more characteristically to the Feast of the Passover than to the Feast of Tabernacles. This latter appears in the oldest law-giving (Exodus 23:16; Exodus 34:22) as חג האסיף, i.e., as a feast of the ingathering of the autumn fruits, and therefore as the closing festival of the whole harvest; it does not receive the historical reference to the journey through the desert, and therewith its character of a feast of booths or arbours, until the addition in Leviticus 23:39-44, having reference to the carrying out of the celebration of the feasts in Canaan; whereas the feast which begins with the full moon of Nisan has, it is true, not been entirely free of all reference to agriculture, but from the very beginning bears the historical names פּסח and חג המּצּות. (3) Because in the Psalm itself, viz., in Psalm 81:6, allusion is made to the fact which the Passover commemorates.
Concerning על־הגּתּית vid., on Psalm 8:1. The symmetrical, stichic plan of the Psalm is clear: the schema is 11. 12. 12.