They indicate between the Vedic Aryans and the Iranians a connection much closer than usually has been assumed.

The bearings of such a connection on the religious ideas of the two peoples are self-evident, and will often have to be touched upon in the course of this history.

It is of less importance, from the present point of view, to say how the Aryans entered India, but since this question is also connected with that of the religious environment of the first Hindu poets, it will be well to state that, although, as some scholars maintain, and as we believe, the Hindus may have come with the Iranians through the open pass of Herat (Haraiva, Haroyu), it is possible that they parted from the latter south of the Hindukush[12] (descending through the Kohistan passes from the north), and that the two peoples thence diverged south-east and south-west respectively.
Neither assumption would prevent the country lying between the Harahvati and Vitast[=a][13] from being, for generations, a common camping-ground for both peoples, who were united still, but gradually diverging.

This seems, at least, to be the most reasonable explanation of the fact that these two rivers are to each people their farthest known western and eastern limits respectively.

With the exception of the vague and uncertain Ras[=a], the Vedic Hindu's geographical knowledge is limited by Kandahar in the west, as is the Iranian's in the east by the Vitast[=a].[14] North of the Vitast[=a] Mount Tricota (Trikakud, 'three peaks') is venerated, and this together with a Mount M[=u]javat, of which the situation is probably in the north, is the extent of modern knowledge in respect of the natural boundaries of the Vedic people.