"The Day of the Lord"
This is essential, for it is directly associated with the object and purpose of the book. The only other place in the whole Bible where we have anything like it is in Daniel 10:5,6, where in every particular the resemblance is the same. His girdle is of gold; His eyes as fire; His feet as brass; His voice as many waters (Rev.), and as a multitude (Dan.); His countenance as the sun (Rev.) and the appearance as lightening (Dan.).
In Daniel it is "a certain man" (Heb. one - a man). In Rev. it is "one like unto the Son of Man." The Two Visions being identical as to the Person and as to His appearance, and also as to the effect on Daniel and John respectively, it is not more than probably that the purpose is also the same in each case?
In Daniel we are expressly told why the Vision was sent. "Now I am come to make thee understand what shall befall thy people in the latter days; for yet the vision is for many days... I will shew thee that which is noted in the scripture of truth" (Dan. 10:14, 21).
The expression, "thy People," is most significant. It is not the Church of God which is in question, but Daniel's People, Israel. This People had been the subject of Daniel's prayer (Dan. 9:4-19). He call them (in speaking to God) "Thy People" (vv. 15, 19); and in the answer to the prayer (9:24), as well as here (10:14) and in 12:1, the angel speaks of them to Daniel as "thy people."*
Is it not certain that this People is the subject, and what is to befall them in the latter day is precisely the import, of the vision which John saw in Rev. 1:13-16. It had been given to that glorious One to show unto His servants things which shall be "hereafter," and that was what was to befall Daniel's people (Israel) "in the latter days."
In Rev. we have "the latter days" - even "the Day of the Lord," and the time has come to show John that which is noted in the scripture of truth. The people, therefore, who are the subjects of the Revelation, are Daniel's People, and not the Church of God.