Who Soma is
Soma is three things at once in the Rigveda: a plant that grew on the mountains, the juice pressed out of it, and a god. The poets do not keep the three apart. When they sing to King Soma they are also singing to the liquid running through the strainer in front of them.
He has a whole book of the Rigveda to himself. All one hundred and fourteen hymns of the ninth book are his, and six more elsewhere. By that count only Indra and Agni receive more. The ninth book is sung over the pressing itself. The stalks are crushed between stones. The juice runs through a filter of sheep's wool and drips, tawny and bright, into wooden vats, where it is mixed with water and milk. The poets call it Pavamana, the one flowing clear, and Indu, the bright drop. They compare the stream to a bull roaring, a horse racing for a prize and a king marching to battle.
The gods drink Soma, and Indra most of all. He drains great draughts of it before he goes out to fight the dragon Vritra, and the hymns say plainly that it is Soma that makes him strong. Men drank it too, and the poets say what it did to them. It made them feel wide awake, safe from sickness and close to the gods.
We have drunk Soma and become immortal. We have reached the light and found the gods. What can an enemy's malice do to us now?
Because he gives that sight, Soma is called a poet and a guide of poets, the one who shows the straightest path. He is also the lord of plants. One hymn asks him to place the singer in the deathless world where the light never fails.
He did not come from the earth. The hymns say that Soma was kept in the highest heaven and that a falcon carried him down while an archer shot at the bird. In one late hymn, the wedding hymn of the tenth book, Soma stands among the constellations and takes the daughter of the Sun as his bride. There the poet says something new, that the Soma the wise know is one nobody on earth ever tastes. He has begun to mean the Moon.