Daniel 10:5

“Then I lifted up mine eyes, and looked, etc.] Being excited to it, by an object presented, of an unusual appearance, which engaged his attention, and caused him to look wistly at it: and, behold a certain man clothed in linen; not Gabriel, but the Son of God, the Messiah; who, though not as yet incarnate, yet was so in the counsel and purpose of God; had agreed in covenant to be man, was promised and prophesied of as such; and now appeared in a human form, as he frequently did before his incarnation, as a pledge of it, and showing his readiness to assume human nature: he appears here “clothed in linen”, in the habit of a priest; which office he sustains, and executes by the sacrifice of…”

“lifted up mine eyes--from the ground on which they had been fixed in his mourning. certain man--literally, "one man." An angel of the highest order; for in Dan 8:16 he commands Gabriel to make Daniel to understand the vision, and in Dan 12:6 one of the two angels inquires of him how long it would be till the end predicted. linen--the raiment of priests, being the symbol of sanctity, as more pure than wool (Exo 28:42); also of prophets (Jer 13:1); and of angels (Rev 15:6). girded with . . . gold--that is, with a girdle interwoven with gold (Rev 1:13).”

“Then I lifted up mine eyes, and looked ... - While he was engaged in devotion. What is here said would lead us to suppose that he had been occupied in deep thought and meditation, perhaps with his eyes fixed on the ground. Behold, a certain man clothed in linen - One who had the form and appearance of a man. The subsequent disclosures showed that he was an angel, but when angels have appeared on earth they have commonly assumed the human form. The margin is, “one.” So also is the Hebrew “one man.” From Daniel 12:6, it would seem that two other such beings appeared in the course of the vision, but either one only was manifest now to Daniel, or his attention was particularly directed to him.…”

“A certain man - Very probably Christ, who appeared to Daniel in royal and priestly robes, and in so great brightness and majesty. Daniel 10:12”

“10:5-6 The man dressed in linen clothing is an unidentified messenger of the Lord (cp. 10:16, 18; 12:6-7; see also Ezek 9:3).”

“and behold: Dan 12:6, Dan 12:7; Jos 5:13; Zac 1:8; Rev 1:13-15 a certain man: Heb. one man clothed: Dan 12:6, Dan 12:7; Eze 9:2 loins: Isa 11:5; Eph 6:14; Rev 1:13-15, Rev 15:6, Rev 15:7 Uphaz: Jer 10:9 Daniel 10:6”