John Gill Commentary Ezekiel 38:7

"Be thou prepared, yea, prepare thyself, thou, and all thy companies that are assembled unto thee, and be thou a guard unto them." — Ezekiel 38:7 (ASV)

Be prepared, and prepare for yourself
All warlike stores and provisions: this is ironically said; and suggests that he would do so, and yet all would be in vain, and to no purpose.

You and all your company, that are assembled to you ;
or all your armies, as the Targum, gathered out of his dominions, and made up of his auxiliaries and allies; let them all be furnished with arms, and everything proper for the expedition designed.

And be a guard to them ;
the general of them; let them observe and obey your word of command; guide and direct, guard and protect them in their march; and take care of them when entered the land of Judea, that they are not exposed to any unnecessary danger, or cut off by any stratagem or ambush: this is also sarcastically said; signifying that let him use all the care and caution that a wise and prudent general can do, yet he and his army should perish.