Thus, in another passage of the same book, the _soma_, in similar language, is said to "lay light in the sun," a phrase scarcely compatible with the moon's sphere of activity[18].
The decision in regard to this question of interpretation is not to be reached so easily as one might suppose, considering that a whole book, the ninth, of the Rig Veda is dedicated to Soma, and that in addition to this there are many hymns addressed to him in the other books.

For in the greater number of passages which may be cited for and against this theory the objector may argue that the generally extravagant praise bestowed upon Soma through the Veda is in any one case merely particularized, and that it is not incongruous to say of the divine _soma_-plant, "he lights the dark nights," when one reads in general that he creates all things, including the gods.

On the other hand, the advocate of the theory may reply that everything which does not apply to the moon-god Soma may be used metaphorically of him.
Thus, where it is said, "Soma goes through the purifying sieve," by analogy with the drink of the plant _soma_ passing through the sieve the poet may be supposed to imagine the moon passing through the sieve-like clouds; and even when this sieve is expressly called the 'sheep's-tail sieve' and 'wool-sieve,' this may still be, metaphorically, the cloud-sieve (as, without the analogy, one speaks to-day of woolly clouds and the 'mare's tail').
So it happens that, with an hundred hymns addressed to Soma, it remains still a matter of discussion whether the _soma_ addressed be the plant or the moon.

Alfred Hillebrandt, to whom is due the problem in its present form, declares that everywhere[19] in the Rig Veda Soma means the moon.

No better hymn can be found to illustrate the difficulty under which labors the _soma_-exegete than IX.