Like Agni, Soma is both a god and a crucial ritual substance, and the boundary between them is not always clear. As has already been discussed, the juice of the soma plant (whatever that may have been), pressed from the plant and elaborately prepared, is the chief offering of the most important complex of rituals, the soma sacrifice. This sacrificial substance and its ritual preparation go back to the Indo-Iranian period, since Avestan attests to the substance haoma, an exact cognate to Sanskrit sóma, and to its pressing and offering (see especially the so-called Hōm Yašt, Y 9–10). In both traditions the substance is also deified.
The “Soma Maṇḍala” of the R̥gveda, Maṇḍala IX, contains 114 hymns dedicated to Soma Pavamāna “Self-Purifying Soma.” These hymns focus entirely on a single ritual moment, the pressing of the plant, the straining of the juice by pouring it over a sheep’s fleece to trap the impurities (twigs and the like), the mixing of the juice first with water and then with milk, and the pouring into containers prior to offering it to the gods, especially Indra. These actions are often presented metaphorically, with Soma conceptualized as a king making a royal progress across the filter and into the cups, a progress that can be compared to the conquering of territory. Or as the Sun in his journey through the cosmos. Or, quite often, as a bull racing to mate with a herd of cows, who represent the milk with which the juice will be mixed.+++(5)+++ Soma is thus regularly presented as having agency in the many descrip tions of the purification of the liquid.
Mythology
Besides this dynamic deification especially characteristic of the IXth Maṇḍala, there is little narrative mythology involving the god Soma. The most important tale is the theft of Soma from heaven, where he was confined in a citadel guarded by an archer called Kr̥śānu. A falcon stole him and brought him to earth, successfully evading serious injury from Kr̥śānu’s arrow, to deliver him to Manu, the first sacrificer. This exploit is mentioned a number of times in the text, but is most fully described in IV.26–27.
Though one characteristic of Soma in later texts, a commonplace already in middle Vedic, is his identification with the moon, this equation is only attested in the very late R̥gveda. It is clearly found only in the Wedding Hymn (X.85), whose first verses depict the wedding of Soma and Sūryā, daughter of the Sun. The bride groom Soma in this hymn has clear lunar qualities, which are distinguished from his identity as an earthy ritual substance.