Revelation 14:13

Here we have the vision of the harvest and vintage, introduced with a solemn preface. Observe, I. The preface, Rev 14:13. Here note, 1. Whence this prophecy about the harvest came: it came down from heaven, and not from men, and therefore it is of certain truth and great authority. 2. How it was to be preserved and published - by writing; it was to be a matter of record, that the people of God might have recourse to it for their support and comfort upon all occasions. 3. What it principally intended, and that is, to show the blessedness of all the faithful saints and servants of God, both in death and after death: Blessed are the dead that die in the Lord from henceforth, etc. Here observe, (1.) The description of those that are and shall be blessed - such as die in the Lord, either die in the cause of Christ, or rather die in a state of vital union with Christ, such as are found in Christ when death comes. (2.) The demonstration of this blessedness: They rest from their labours, and their works do follow them. [1.] They are blessed in their rest; they rest from all sin, temptation, sorrow, and persecution. There the wicked cease from troubling, there the weary are at rest. [2.

— Matthew Henry's Concise Commentary (public domain)

Encouragement to cheer those persecuted under the beast. Write--to put it on record for ever. Blessed--in resting from their toils, and, in the case of the saints just before alluded to as persecuted by the beast, in resting from persecutions. Their full blessedness is now "from henceforth," that is, FROM THIS TIME, when the judgment on the beast and the harvest gatherings of the elect are imminent. The time so earnestly longed for by former martyrs is now all but come; the full number of their fellow servants is on the verge of completion; they have no longer to "rest (the same Greek as here, anapausis) yet for a little season," their eternal rest, or cessation from toils (Th2 1:7; Greek, "anesis," relaxation after hardships. Heb 4:9-10, sabbatism of rest; and Greek, "catapausis," akin to the Greek here) is close at hand now. They are blessed in being about to sit down to the marriage supper of the Lamb (Rev 19:9), and in having part in the first resurrection (Rev 20:6), and in having right to the tree of life (Rev 22:14). In Rev 14:14-16 follows the explanation of why they are pronounced "blessed" now in particular, namely, the Son of man on the cloud is just coming to gather them in as the harvest ripe for garner.

— Jamieson-Fausset-Brown Commentary (public domain)