Who maketh his angels spirits - The meaning here literally would be, "Who makes the winds his messengers," or "his angels;" that is, who employs them to execute his purpose; who sends them out as messengers or angels to do his will.
His ministers a flaming fire - That is, Fire is employed by him - in lightnings - to accomplish his purpose as his ministers or his servants. They are entirely under his command. They are sent by him to do his will; to carry out his designs. This is intended to describe the majesty and the power of God - that he can employ wind and lightning - tempest and storm - to go on errands such as he commands; to fulfill his plans; to do his bidding. For the application of this to the angels, and as employed by the apostle Paul to prove the inferiority of the angels to the Messiah, see the notes at Hebrews 1:7.

עשה מלאכיו רחות oseh rnalachaiv ruchoth,
משרתיו אש להט mesharethaiv esh lohet.
The elements are described as prompt and expedite to perform the Divine commands, like angels or ministers serving in the tabernacle; the Hebrew word משרתיו mesharethaiv being a word most common in the sacred ministrations.

Who (b) maketh his angels spirits; his ministers a flaming fire:
(b) As the prophet here shows that all visible powers are ready to serve God: so in (Hebrews 1:7) the angels also, are obedient to his commandment.

Who maketh his angels spirits,.... The angels are spirits, or spiritual substances, yet created ones; and so differ from God, who is a spirit, and from the Holy Spirit of God, who are Creators and not creatures; angels are spirits without bodies, and so differ from the souls or spirits of men, and are immaterial, and so die not; these are made by Christ, by whom all things are made, Colossians 1:16 and so he must be greater and more excellent than they; for which purpose the passage is quoted in Hebrews 1:7. Some render it, "who maketh his angels as the winds"; to which they may be compared for their invisibility, they being not to be seen, no more than the wind, unless when they assume an external form; and for their penetration through bodies in a very surprising manner; see Acts 12:6, and for their great force and power, being mighty angels, and said to excel in strength, Psalm 103:20, and for their swiftness in obeying the divine commands; so the Targum,
"he maketh his messengers, or angels, swift as the wind.''
His ministers a flaming fire; angels are ministers to God, stand before him, behold his face, wait for and listen to his orders, and execute them; they are ministers to Christ, they were so at his incarnation, in his infancy, when in the wilderness and in the garden, at his resurrection and ascension, and will attend him at his second coming; and these are ministers to his people, take the care of them, encamp about them, do many good offices to them in life, and at death carry their souls to Abraham's bosom: these are made a flaming fire, or "as" flaming fire, for their force and power; so the Targum,
"his ministers strong as flaming fire;''
and for their swiftness as before; and because of their burning love to God, Christ, and his people, and their flaming zeal for his cause and interest; hence thought by some to be called "seraphim": and because they are sometimes the executioners of God's wrath; and have sometimes appeared in fiery forms, as in forms of horses of fire and chariots of fire, and will descend with Christ in flaming fire at the last day; see 2-Kings 2:11. Some invert the words, both reading and sense, thus, "who maketh the winds his angels, or messengers, and flaming fire his ministers"; so Jarchi, Aben Ezra, and Kimchi; we read of stormy wind fulfilling his word, Psalm 148:8, he sends out his winds at his pleasure to do his errands; as to dry up the waters of the flood, to drive back the waters of the Red sea, and make dry land, to bring quails from thence, and scatter them about the camp of Israel, and in many other instances. So flaming fire was used as his ministers in burning Sodom and Gomorrah; and multitudes of the murmuring Israelites, and the captains with their fifties; but this sense is contrary to the order of the words, and the design of them, and to the apostle's sense of them, Hebrews 1:7 which is confirmed by the Targum, Septuagint, and all the Oriental versions.

This is quoted by Paul (Hebrews 1:7) to denote the subordinate position of angels; that is, they are only messengers as other and material agencies.
spirits--literally, "winds."
flaming fire-- (Psalm 105:32) being here so called.

Spirits - Of a spiritual or incorporeal nature, that they might be fitter for their employments. Fire - So called for their irresistible force and agility, and fervency in the execution of God's commands.