The day of the Lord is a powerful concept in, especially, the prophets, and it's a very complex term and one that really exemplifies the richness of our Christian faith and our Christian hope. In the prophets, the day of the Lord really was this hoped for time when God would again visit his people. As the prophets talk about it, they talk about it in two different ways. First of all, as a day of judgment against, first of all, the people of Israel and a day of judgment against their enemies, but also a day of salvation for his people. And what's interesting about the way the prophets talk about the day of the Lord is the way that they talk about it from two different reference points, or two different perspectives. Because, on the one hand, that day of both judgment and salvation when God would visit his people is seen as a historical day, a day when the prophets could see on the historical horizon, horizon coming. So, for example, we see a physical manifestation of that day in the invasion of Babylon and the exile of the people, and we see the day of salvation then coming when the Lord brought his people from exile as he had promised them. But beyond that, there is also the eschatological day, the ultimate day, of judgment and salvation for God's people. And so, we see the prophets talking more universal eschatological language about the judgment of God's enemies and the enemies of his people, and also the ultimate salvation of his people in the eschaton, in the last days, in the last time. And the interesting thing, I think, about the way that the prophets talk about that day is that sometimes it's hard to distinguish one from the other, whether the prophets are talking about the historical day or the eschatological day. Sometimes their speech blends in from one to the other, and the reason they do that is because the prophets want us to see the one in connection with the other. In other words, the historical days of judgment and salvation that we see God at work in history are ultimately foreshadowings or foretastes of the ultimate day of salvation. So that, for example, in the book of Joel you have the interesting case in which he seems to go from the historical day to the eschatological day, and sometimes he's talking about what seems to be the historical day, but dresses it up in universal or eschatological language, especially in Joel 2, which I would invite you to read sometime. And so, it's very interesting to see that. Notice that the day of judgment, when we're talking especially about eschatological in eschatological terms, is a day in which, as I said before, the enemies would be judged, creation would be undone. The day of grace, or salvation, is filled with the presence of Yahweh amongst his people, the emphasis on the forgiveness of their sins, the renewal of creation; you see the promise of universal peace and unity among God's people. So, the theme, the day of the Lord, is one of those themes that unifies the Old Testament, I think, and – in both the Old and the New Testament – it's a rich term that we, as God's people, ought to consider and think about, look forward to, and hope to have come to pass as we look forward to that day.