Jamieson, Fausset and Brown on Isaiah 13:2

2. Lift ... banner--(Is 5:26; 11:10).

the high mountain--rather, "a bare (literally, "bald," that is, without trees) mountain"; from it the banner could be seen afar off, so as to rally together the peoples against Babylon.

unto them--unto the Medes (Is 13:17), the assailants of Babylon. It is remarkable that Isaiah does not foretell here the Jews' captivity in Babylon, but presupposes that event, and throws himself beyond, predicting another event still more future, the overthrow of the city of Israel's oppressors. It was now one hundred seventy-four years before the event.

shake ... hand--beckon with the hand--wave the hand to direct the nations to march against Babylon.

nobles--Babylonian. Rather, in a bad sense, tyrants; as in Is 14:5, "rulers" in parallelism to "the wicked"; and Job 21:28 [Maurer].