The Persian empire at that time was of such vast extent, that it reached from the river Indus to the Mediterranean, and the Euphrates was looked upon as naturally dividing it into two parts, east and west.
Nehemiah asks, ch.ii.7, for letters to the governors of the western division of the empire, that they may be instructed to help him and forward him on his way.
He asks, ver.

8, for something more.

There is a certain man named Asaph, who has charge of the king's forest or park (see margin of R.V.).

The real word which Nehemiah used was paradise--the king's paradise.

The derivation of the word is from the Persian words Pairi, round about, and Deza, a wall.