“Elijah the prophet.” “Elijah” was John the Baptist (Matt. 17:10-13). Calling John the Baptist “Elijah” is the figure of speech antonomasia, “name change,” where a person is called by a name other than his or her own name in order to import characteristics from the other person. For more on Elijah and John the Baptist, see commentary on Matthew 17:10.
“Day of Yahweh.” The phrase, “Day of Yahweh,” which is translated as “Day of the LORD” in most English versions is one of the more common terms that refers to the end times, and it can refer to the end times as a whole, or it can refer to a specific part of the end times. The meaning of the phrase must be determined from the context.
By far the majority of the times the phrase, “the Day of the Lord” is used, it is associated with wrath and destruction, and thus refers to the tribulation and destruction that will precede the Second Coming of Christ (cp. Ezek. 30:3, Joel 1:15; 2:1; Amos 5:20; Zephaniah 1:7ff; 1:14ff; Malachi 4:1-5; 1 Thess. 5:2; 2 Pet. 3:10). For example, in Isaiah 13, the day of the Lord is referred to as a “cruel day,” in which people will “wail,” and there is wrath and destruction (cp. Isa. 13:6, 9), and that cruel day is the Tribulation period before the actual Day of Judgment.
Some verses connect the Day of the Lord with the judgment that follows the tribulation (Joel 2:31; 3:14). Some Jews connected the Day of the Lord with God’s judgment of the nations, without properly realizing that they themselves would also go through the period of God’s wrath and the Judgment, but everyone alive on earth when the Tribulation occurs will experience it (Amos 5:18-20). Furthermore, the Jews will not get special treatment at the Judgment, but will be judged based on how they lived and what they did in this life, just as everyone else. The Old Testament scriptures, Jesus, John the Baptist, and the New Testament all with one voice warn the Jews not to think of themselves as special just because they are Jews, but to obey God if they want to do well on the Day of Judgment.
Sometimes it can be difficult or impossible to tell exactly in any given context if the phrase “Day of the LORD,” or equivalent phrases such as “that Day,” includes the Judgment itself or just refers to the tribulation that precedes it. When used to refer to the end times, “the Day of the Lord” can encompass the Tribulation that precedes the Second Coming of Christ, the Second Coming itself and the Battle of Armageddon, the judgments that follow Christ’s conquest of the earth, and the Millennial Kingdom of Christ on earth.