Indian tradition distinctly asserts that there was an Aila outflow of the Druhyus through the northwest into the countries beyond where they founded … - Frederick Eden Pargiter

[tradition] makes the Aila power begin at Allahabad and yet distinctly suggests that they came from outside India.

The next Druhyu king Gandhāra retired to the northwest and gave his name to the Gandhāra country.

"If the Aryans had entered India from the north-west, and had advanced eastward through the Punjab only as far as the Saraswati or Jumna when the Rigvedic hymns were composed, it is very surprising that the hymn arranges the rivers, not according to their progress, but reversaly from the Ganges which they had hardly reached. " Imam me gange yamune sarasvati sutudri stomam sacata parusnaya asiknya marudvrdhe vitastayarjikiye srnuhya susomaya " (x 75.05) O Ganga, Yamuna, Sarasvati, Sutudri (Sutlej), Parushini (Ravi), hear my praise! Listen to my call, Asikni (Chenab), Marudvridha (Maruvardhvan), Vitasta (Jhelum) with Arjikiya, Sushoma (Sohan).