Cherubim's are winged celestial beings also referred to as a form of angel who protect and vindicate (prove, justify, confirm) the righteousness of God. See Bible verses about cherub and cherubim below.
The Lord rode upon a cherub: 2 Samuel 22:7 In my distress I called upon the LORD, and cried to my God: and he did hear my voice out of his temple, and my cry did enter into his ears. 2 Samuel 22:8 Then the earth shook and trembled; the foundations of heaven moved and shook, because he was wroth. 2 Samuel 22:9 There went up a smoke out of his nostrils, and fire out of his mouth devoured: coals were kindled by it. 2 Samuel 22:10 He bowed the heavens also, and came down; and darkness was under his feet. 2 Samuel 22:11 And he rode upon a cherub, and did fly: and he was seen upon the wings of the wind. 2 Samuel 22:12 And he made darkness pavilions round about him, dark waters, and thick clouds of the skies. 2 Samuel 22:13 Through the brightness before him were coals of fire kindled. 2 Samuel 22:14 The LORD thundered from heaven, and the most High uttered his voice. 2 Samuel 22:15 And he sent out arrows, and scattered them; lightning, and discomfited them. First mention of Cherubim's in the Bible: Cherubim's are protectors. The first mention of cherubim in the Bible is when God drove Adam and Eve from the garden of Eden after they had eaten from the tree God had told them not too. God placed Cherubim's on the East side of the garden with a flaming sword which turned in every direction to protect the tree of life.
Genesis 3:23 Therefore the LORD God sent him forth from the garden of Eden, to till the ground from whence he was taken.
Genesis 3:24 So he drove out the man; and he placed at the east of the garden of Eden Cherubim's, and a flaming sword which turned every way, to keep the way of the tree of life.
King David referred to Cherubim's as protectors:
Psalm 80:1 Give ear, O Shepherd of Israel, thou that leadest Joseph like a flock; thou that dwellest between the cherubims, shine forth.
Ezekiel seen Cherubim's in a dream referring to them as protectors and described what they looked like.
Ezekiel 10:1 Then I looked, and, behold, in the firmament that was above the head of the cherubims there appeared over them as it were a sapphire stone, as the appearance of the likeness of a throne.
Ezekiel 10:2 And he spake unto the man clothed with linen, and said, Go in between the wheels, even under the cherub, and fill thine hand with coals of fire from between the cherubims, and scatter them over the city. And he went in in my sight.
Ezekiel 10:3 Now the cherubims stood on the right side of the house, when the man went in; and the cloud filled the inner court.
Ezekiel 10:4 Then the glory of the LORD went up from the cherub, and stood over the threshold of the house; and the house was filled with the cloud, and the court was full of the brightness of the LORD's glory.
Ezekiel 10:5 And the sound of the cherubims' wings was heard even to the outer court, as the voice of the Almighty God when he speaketh.
Ezekiel 10:6 And it came to pass, that when he had commanded the man clothed with linen, saying, Take fire from between the wheels, from between the cherubims; then he went in, and stood beside the wheels.
Ezekiel 10:7 And one cherub stretched forth his hand from between the cherubims unto the fire that was between the cherubims, and took thereof, and put it into the hands of him that was clothed with linen: who took it, and went out.
Ezekiel 10:8 And there appeared in the cherubims the form of a man's hand under their wings.
Ezekiel 10:9 And when I looked, behold the four wheels by the cherubims, one wheel by one cherub, and another wheel by another cherub: and the appearance of the wheels was as the colour of a beryl stone.
Ezekiel 10:10 And as for their appearances, they four had one likeness, as if a wheel had been in the midst of a wheel.
Ezekiel 10:11 When they went, they went upon their four sides; they turned not as they went, but to the place whither the head looked they followed it; they turned not as they went.
Ezekiel 10:12 And their whole body, and their backs, and their hands, and their wings, and the wheels, were full of eyes round about, even the wheels that they four had.
Ezekiel 10:13 As for the wheels, it was cried unto them in my hearing, O wheel.
Ezekiel 10:14 And every one had four faces: the first face was the face of a cherub, and the second face was the face of a man, and the third the face of a lion, and the fourth the face of an eagle.
Ezekiel 10:15 And the cherubims were lifted up. This is the living creature that I saw by the river of Chebar.
Ezekiel 10:16 And when the cherubims went, the wheels went by them: and when the cherubims lifted up their wings to mount up from the earth, the same wheels also turned not from beside them.
Ezekiel 10:17 When they stood, these stood; and when they were lifted up, these lifted up themselves also: for the spirit of the living creature was in them.
Ezekiel 10:18 Then the glory of the LORD departed from off the threshold of the house, and stood over the cherubims.Ezekiel 10:19 And the cherubims lifted up their wings, and mounted up from the earth in my sight: when they went out, the wheels also were beside them, and every one stood at the door of the east gate of the LORD's house; and the glory of the God of Israel was over them above.
Ezekiel 10:20 This is the living creature that I saw under the God of Israel by the river of Chebar; and I knew that they were the cherubims.
Ezekiel 10:21 Every one had four faces apiece, and every one four wings; and the likeness of the hands of a man was under their wings.
Ezekiel 10:22 And the likeness of their faces was the same faces which I saw by the river of Chebar, their appearances and themselves: they went every one straight forward.
Ezekiel had a dream and described what is believed to be cherubim's which Biblical scholars believe the cherubim is symbolic of God's Holy presence and gives credence to the fact that God is unapproachable. Ezekiel Chapter 1 Cherubim's were on the Ark of the Covenant:
Hebrews 9:1 Then verily the first covenant had also ordinances of divine service, and a worldly sanctuary.
Hebrews 9:2 For there was a tabernacle made; the first, wherein was the candlestick, and the table, and the shewbread; which is called the sanctuary.
Hebrews 9:3 And after the second veil, the tabernacle which is called the Holiest of all;
Hebrews 9:4 Which had the golden censer, and the ark of the covenant overlaid round about with gold, wherein was the golden pot that had manna, and Aaron's rod that budded, and the tables of the covenant;
Hebrews 9:5 And over it the cherubims of glory shadowing the mercyseat; of which we cannot now speak particularly.
Hebrews 9:6 Now when these things were thus ordained, the priests went always into the first tabernacle, accomplishing the service of God.