The Zend Avesta, Part I (SBE04): Vendîdâd: Fargard I

'Vaêkereta, of the evil shadows' (8), is identified with Kapul (Cabul); whether rightly or wrongly, we are unable to decide; yet, as it is spoken of only as the seat of the adventures of Keresâspa (see Introd. IV, 21), it may be suspected that this assimilation rests merely on the fact that, in later tradition, the legend of Keresâspa was localised in the table-land of Peshyansâi, in Kabulistan (Bund. XXX). In the enumeration there is no apparent order whatever, and Ormazd, in his creations, seems to travel all over the map, forward and backward, without the slightest regard to the cardinal points. Yet, the starting point and the final point have not been arbitrarily chosen: the first land created was 'the Airyana Vaêgô by the Vanguhi Dâitya,' and the last was the land by the Rangha. Now, p. 3 the Vanguhi and the Rangha were originally the celestial rivers that came down from heaven (as two heavenly Gaṅgâs) to surround the earth, the one in the east, the other in the west (Bund. XX); this is why the creation begins with a land by the Vanguhi and ends with a land by the Rangha. In the Sassanian ages, when the Tigris was definitively the border of Iran in the west, the Rangha was identified with it, and the sixteenth land is accordingly described in the Commentary as being Arvastân-i-Rûm, or Roman Mesopotamia. But all the Avesta passages in which the Rangha is cited refer to its mythical nature, as the river in the far-off horizon, as the surrounding Okeanos, and, now and then, still resembling its Vedic homonym, the Rasâ, as the river that divides the gods from the fiends.