Daniel 10:1

In the (a) third year of Cyrus king of Persia a thing was revealed unto Daniel, whose name was called Belteshazzar; and the thing [was] true, but the time appointed [was] (b) long: and he understood the thing, and had understanding of the vision.

(a) He notes this third year, because at this time the building of the temple began to be hindered by Cambyses, Cyrus's son, when the father made war in Asia minor against the Scythians, which was discouraging to the godly, and fearful to Daniel.

(b) Which is to declare that the godly should not hasten too much, but patiently abide the fulfilment of God's promise.