Yechezk'el 9:1-2 Then I heard Him call out in a loud voice, "Bring the guards of the city here, each with a weapon in his hand." And I saw six men coming from the direction of the upper gate, which faces north, each with a deadly weapon in his hand. With them was a man clothed in linen who had a writing kit at his side. They came in and stood beside the bronze altar.
I heard Him - Yechezk'el heard the voice of G-d the Father. This is a continuation of chapter 8 where He was referred to as Adonai Elohim in verse 1.
The guards of the city - These are six angels with the appearance of men. Their weapons are drawn and they are about to carry out the commands of G-d the Father.
With them was a man clothed in linen who had a writing kit at his side. - This is yet another appearance of Yeshua, G-d the Son. We can tell this by the fact that He is set apart from the other six. He is dressed in linen, symbolizing His purity and identifying Him as the High Priest of heaven.
Hebrews 4:14 Since then we have a great high priest who has passed through the heavens, Yeshua the Son of G-d, let us hold fast our confession.
Yechezk'el 9:3-4 Now the glory of the G-d of Israel went up from above the cherubim, where it had been, and moved to the threshold of the temple. Then the L-RD called to the man clothed in linen who had the writing kit (cup) at his side and said to him, "Go throughout the city of Yerushalayim (Jerusalem) and put a mark on the foreheads of those who grieve and lament over all the detestable things that are done in it."
The glory of the G-d - dwelt above the Mercy seat. This was another name for Ruach HaKodesh, G-d the Spirit.
So here in the first 3 verses of this chapter, we can clearly see the 3 persons of the tri-unity of G-d. :~)
Only Yeshua could stand by the Shekinah glory and live at this point.
The glory of the L-rd finally departs the Holy of Holies. He stops at the keruv (threshold) of the temple. In the following chapters we will see Him leave completely. The fact that it took this long shows the longsuffering of HaShem. He still is long suffering when it comes to the apple of His eye-Israel. His glory wants to return to Israel and the temple and will one day after Yeshua's return. What is so wonderful today is that the glory of the L-rd will never leave those who have trusted in Yeshua. We don't ever have to worry about this happening to us. Praise HaShem, Praise Yeshua, and Praise Ruach HaKodesh. Yeshua also promises never to leave us nor forsake us. He is alive in us and continues to work through us. The work He does in us has been prepared beforehand for us.
Ephesians 2:8-10 For by mercy you have been saved through faith; and that not of yourselves, it is the gift of G-d; not as a result of works, that no one should boast. For we are His workmanship, created in Yeshua HaMashiach for good works, which G-d prepared beforehand, that we should walk in them.
The word translated "mark" here was the letter "Tav" in Hebrew, the last letter of the Hebrew alphabet. It means truth and perfection. At the time the book of Yechezk'el (Ezekiel) was written the letter "Tav" looked like a "t". A little cross! So HaShem was telling them that salvation would come though the lamb who would be slain on the cross (execution stake). :~)
A mark on the foreheads - Yeshua marks those on the forehead those that had a grievous heart over the detestable things that were done. In the future, HaShem will also mark the 144,000 of those that tell others the good news about Yeshua during the time of Ya'akov's trouble.
Revelation 14:1-5 And I looked, and look, the Lamb was standing on Mount Zion, and with Him one hundred and forty-four thousand, having His name and the name of His Father written on their foreheads. And I heard a voice from heaven, like the sound of many waters and like the sound of loud thunder, and the voice which I heard was like the sound of harpists playing on their harps. And they sang a new song before the throne and before the four living creatures and the elders; and no one could learn the song except the one hundred and forty-four thousand who had been purchased from the earth. These are the ones who have not been defiled with women, for they have kept themselves chaste. These are the ones who follow the Lamb wherever He goes. These have been purchased from among men as first fruits to G-d and to the Lamb. And no lie was found in their mouth; they are blameless.
We also know whatever HaShem does the prince of the power of the air, HaSatan, likes to copy.
Revelation 13:15-18 And there was given to him to give breath to the image of the beast, that the image of the beast might even speak and cause as many as do not worship the image of the beast to be killed. And he causes all, the small and the great, and the rich and the poor, and the free men and the slaves, to be given a mark on their right hand, or on their forehead, and he provides that no one should be able to buy or to sell, except the one who has the mark, either the name of the beast or the number of his name. Here is wisdom. Let him who has understanding calculate the number of the beast, for the number is that of a man; and his number is six hundred and sixty-six.
The corresponding letter to this chapter is Tet-serpent; objective good - that which appears evil but is for our improvement.