Pahlavi Texts, Part II (SBE18), E.W. West, tr. , at sacred-texts.com
1. As to the sixty-ninth question and reply, that which you ask is thus: What are these river-beds 3, and what is the cause of them; whence do they always arise, and why is there not a river-bed every-where and in every place where there is no mountain?
2. The reply is this, that any place where a mountain is not discernible and a river-bed exists it is a fissure (askûpŏ); and it is declared as clear that, even before the growth of the mountains, when the earth was all a plain, by the shaking of the world the whole world became rent (zandakŏ) 4. 3. Even
[paragraph continues] Frâsîyâv of Tûr 1 was specially mighty by causing the construction of channels (vidarg) there where it is mountainous, and also in low-lands 2, in which there is no mountain, and the shaking in its creation was the formation of great sunken 3 springs and river-beds. 4. And if it has been prepared in, or if it be in a ravine (sikaftŏ) of, the mountains, the cause, too, of the contraction, thundering, and tearing of a river, if its confinement be in the earth, is the resistance which it meets in seeking a passage; and as it is a spring of the waters of the earth, so also it is in the earth, whose contraction and panting are mighty and full of strength. 5. And when it is a time that they would make a constructed channel at the outside of its ravine, as regards the contraction which is within it, the resistance by which it is contracted at the outside of the ravine is the ground 4.
213:3 There is some doubt as to whether the word should be read zôgakŏ (comp. Pers. zôgh, 'a river'), or zandakŏ (comp. Pers. zandah, 'fissured'), but the meaning is tolerably certain from the context.
213:4 When the evil spirit rushed into the earth it is said to have shaken, and the mountains began to grow (see Bd. VIII, 1-5); and at the resurrection it is expected that the earth will recover its original perfect state of a level plain (see Bd. XXX, 33).
214:1 Frangrasyan, the Tûryan, in the Avesta; called Afrâsiyâb in the Shâhnâmah (see Bd. XXXI, x4). He is often mentioned as constructing canals (see Bd. XX, 17, 34, XXI, 6), but being a foreign conqueror he was considered as specially wicked by the Irânians.
214:2 Assuming that sîtân is a miswriting of sîpŏân, occasioned by joining two of the letters, just as harvispŏ, 'all,' is often written harvist.
214:3 Or, perhaps, 'hidden.'
214:4 That is, a watercourse which is confined by its natural rocky channel in the mountains, when carried across the plain in a canal, is confined only, by softer soil.