NOTES for Hos 9:5
Hosea, like his predecessor and older contemporary Amos, more than once turned to the theme of celebrating the day of Yahweh, or the day of the Lord. In their time it was one of the chief Yahwist feasts. It was celebrated both in Judea, in Jerusalem, and in the North, in the Samaritan kingdom, at Bethel, which was the religious capital of Samaria. But regardless of place, this feast was connected with the expected triumph of Yahweh and of Yahwism, awaited both in the South and in the North. There is nothing surprising here: everyone who came on the day of Yahweh to the Temple of Jerusalem or Bethel was sure that the day of Yahweh's triumph would also become the day of the triumph of Yahwism and therefore of their own triumph, since none of those who came doubted that he belonged to the people of God.
Of course, most of those who came remembered their religion only several times a year, and many had problems following the Torah and keeping the commandments. Yet, as one can see, those who came hoped that with a splendid feast and numerous abundant sacrifices they would compensate both for everyday indifference to spiritual life and for a certain neglect of morality. The prophet, meanwhile, reminds them that one cannot buy God off with sacrifices alone. Nor do sacrifices exist for the purpose of buying Him off. A sacrifice is a shared meal of God and people; that is its original meaning.
Every attempt to use sacrifice as a means to "appease" God is nothing other than the spiritual degeneration of the corresponding tradition, which of course did occur, but was never approved either by God or by His servants. This is understandable: in such a case, instead of the expected sanctification of the people by God, there was real profanation. That is why the prophet warns his listeners that the day of Yahweh may turn out for them not to be a day of triumph, but a day of Judgment. For, as the apostle will say much later, Judgment begins with the house of God.