John the Apostle
Revelation 6:1BSB·traditional attribution

Then I watched as the Lamb opened one of the seven seals, and I heard one of the four living creatures say in a voice like thunder, “Come!”

Matthew Henry Presbyterian @wholebiblehenry

Here, 1. Christ, the Lamb, opens the first seal; he now enters upon the great work of opening and accomplishing the purposes of God towards the church and the world. 2. One of the ministers of the church calls upon the apostle, with a voice like thunder, to come near, and observe what then appeared. 3. We have the vision itself, Rev 6:2.

Commenting on Revelation 6:1-2

John Gill Reformed Baptist @doctorgill

And I saw, when the Lamb opened one of the seals,.... Of the sealed book; one of the seven seals of it, as read the Alexandrian copy, the Vulgate Latin, and the Oriental versions, and the Complutensian edition; that is, the first; so "one" is used for first in Gen 1:5; and as appears from the following seals being called second, third, fourth, &c.

Albert Barnes Presbyterian @notesbybarnes

CHAPTER VI ANALYSIS OF THE CHAPTER THIS chapter contains an account of the opening of six of the seven seals. It need hardly be said to any one who is at all familiar with the numerous--not to say numberless--expositions of the Apocalypse, that it is at this point that interpreters begin to differ, and that here commences the divergence towards those various, discordant, and many...