Albert Barnes Commentary Daniel 8:4

"I saw the ram pushing westward, and northward, and southward; and no beasts could stand before him, neither was there any that could deliver out of his hand; but he did according to his will, and magnified himself." — Daniel 8:4 (ASV)

I saw the ram pushing westward, and northward, and southward - This denotes the conquests of the united kingdom. The east is not mentioned, for none of the conquests of the Medo-Persian empire extended in that direction. Yet nothing could better express the conquests actually made by the Medo-Persian empire than this representation.

On the west the conquests embraced Babylonia, Mesopotamia, Syria, and Asia Minor; on the north, Colchis, Armenia, Iberia, and the regions around the Caspian Sea; and on the south, Palestine, Ethiopia, Egypt, and Lybia. - Lengerke.

This Medo-Persian power is represented as coming from the east. (Isaiah 41:2): who raised up the righteous man from the east, etc.; (Isaiah 46:11): calling a ravenous bird from the east, etc.

He did according to his will, and became great - This also expresses well the character of the Medo-Persian empire. It extended over a great part of the known world, subduing to itself a large portion of the earth. In its early conquests it met with no successful opposition, nor was it halted until it was subdued by Greece—as at Leuctra and Marathon—and then as it was finally overthrown by Alexander the Great.