Let us meditate on OM the imperishable, the beginning of prayer.
For as the earth comes from the waters, plants from earth, and man from plants, so man is speech, and speech is OM. Of all speech the essence is the Rig Veda, but Sama is the essence of Rig, and of Sama the essence is OM, the Udgitha.
This is the essence of essences, the highest, the eight rung, venerated above all that human beings hold holy. OM is the Self of all.