Above it stood the seraphims: each one had six wings; with twain he covered his face, and with twain he covered his feet, and with twain he did fly. – Isaiah 6:2

In this vision Isaiah saw the flaming spirits that wait upon Christ of God. He calls them “seraphims.” The best interpretation we can give is “burning ones:” they burn in the sense of consuming. They burn up that which ought to be consumed, namely, all kinds of evil. There are powers around our Lord which will destroy evil. You ask me to tell you something about these seraphim; how can I? They have covered their faces, and covered their feet. Since nothing is to be seen, what can I tell you? Neither would it be right for us to speak concerning them, for manifestly it is their desire to be hidden. Who will violate their wish to be concealed? They covered their faces, they covered their feet, and therein they did as good as they say, “Look not on us, but look on Him who sits upon the throne, whose attendants we are.” This much is all we know,-exalted intelligences are in waiting upon our Lord, and are able to fly swiftly at His bidding. Tremble not concerning this error, or that, it shall be burnt up by those agencies which are at the command of our exalted Lord. Spirits from God shall run to and fro, and smite, as with the fire of God, those powers of darkness which now oppress our race. God Himself is a consuming fire: who can dwell with Him but those that are like Him? He maketh His ministers a flame of fire. Around our Lord are the chariots of God, which are twenty thousand, even thousands of angels. His power knows no limit. His word runneth very swiftly; He speaks, and it is done; He commands, and it stands fast. Glory be unto Thee, O Christ! We will not fear nor be discouraged, since these Thy servants are ready to flame forth at Thy bidding. Truly Thou art Jehovah of hosts.~ C.H. Spurgeon

https://www.blueletterbible.org/Comm/spurgeon_charles/sermons/1844.cfm