מדרש אויף במדבר 19:5

7) If it is written in respect to zav (that what is detached from him is clean), why need it be written in respect to mishkav? (See Section 2:3); and if it is written in respect to mishkav, why need it be stated in respect to zav?) Because there obtains with zav what does not obtain with mishkav, and with mishkav what does not obtain with zav — Zav makes a mishkav, and mishkav does not make a zav; the attachments of a zav are tahor (viz. Bamidbar 19:5 above) and the attachments of a mishkav are tamei (See Section 3:4) — Because there obtains with zav what does not obtain with mishkav and with mishkav what does not obtain with zav, it must be written both in respect to mishkav and in respect to zav.

(Numb. 19:5:) AND HE SHALL BURN THE HEIFER (Rome) BEFORE HIS EYES. Thus it is stated (in Dan. 7:11): <I LOOKED ON UNTIL THE BEAST WAS SLAIN AND ITS BODY DESTROYED,> GIVEN OVER FOR BURNING IN THE FIRE.

(Numb. 19:5, cont.:) TOGETHER WITH ITS SKIN, ITS FLESH, AND ITS BLOOD. These represent its commanders,¹³⁵Lat.: duces. its governors,¹³⁶Gk.: eparchoi or possibly hyparchoi. and {the} [its] generals.¹³⁷Gk.: stratelatai. This is what is written (in Ezek. 27:27): YOUR WEALTH, YOUR WARES, YOUR MERCHANDISE, YOUR MARINERS, YOUR SAILORS, YOUR LEAK REPAIRERS, THOSE WHO TRADE YOUR WARES, <ALL YOUR MEN OF WAR WHO ARE IN YOUR MIDST, WITH ALL YOUR ASSEMBLY THAT IS IN YOUR MIDST>, WILL SINK INTO THE HEART OF THE SEAS ON THE DAY OF YOUR DOWNFALL. R. Samuel bar Isaac said: Even those who were outside your assembly, but who came and attached themselves to your assemblies, they also will sink into the heart of the seas on the day of your downfall.