Charles Ellicott Commentary Isaiah 66:20

"And they shall bring all your brethren out of all the nations for an oblation unto Jehovah, upon horses, and in chariots, and in litters, and upon mules, and upon dromedaries, to my holy mountain Jerusalem, saith Jehovah, as the children of Israel bring their oblation in a clean vessel into the house of Jehovah." — Isaiah 66:20 (ASV)

They shall bring all your brothers ... —The offering is the minchah, the bloodless meatoffering of the Levitical law (Leviticus 2:1–2). The underlying thought is that the returning exiles would be the most acceptable offering that could be brought to Jehovah. The same idea appears in Zephaniah 3:10, and a similar one, transferred, however, to the Gentile converts, in Romans 15:16.

Upon horses, and in chariots ... —The list of the modes of transport, as in Zechariah 14:15, points to the various habits of the many nations who are to be sharers in the work.

As the children of Israel ... —The “clean offering” is, as before, the minchah. The nations, or, perhaps, even the chariots and litters on which they brought the exiles, are as the “clean vessels” in which the minchah was brought to the Temple.