"There is a peculiarity about these points of resemblance which is not so commonly known: It is the eighth Mandala which bears the most striking similarity to the Avesta. There and there only (and of course partly in the related first Mandala) do some common words like uṣṭra and the strophic structure called pragātha occur. … Further research in this direction is sure to be fruitful."
Mandala 8

January 1, 1970