Chandogya Upanishad is associated with the Kauthuma Shakha of the Sama Veda. It is part of the Chandogya Brahmana, which has ten chapters. The Chhaudogya Upanishad comprises of eight chapters, and commences on the Om Mantra. Chandogya Upanishad is the part of Chandogya Brahaman that contains ten chapters. The 3rd Khanda of First Chapter of the Chandogya Upanishad deals with the meditation on the Udgitha as the Sun and the Vyana. Here the meditation on the Udgitha is done with reference to the gods. According to it one must meditate on the Udgitha as the sun who provides warmth. When the sun rises one must sing the Udgitha for welfare of the creation. With the rising of the sun all the darkness and fear disappears. One who realises this becomes the destroyer of all darkness and fear. The vital breath or the Prana and the sun are alike. Both are warm as well as that; the Prana may be called transitive; the sun may also be called transitive and retransitive. Thus, both of them must be adored as the Udgitha. One should meditate on the Udgitha as the vyana. That by which breath is respired is Prana, that by which it is inspired is Apana, and the interval of the two is Vyana, which is speech. Therefore when one utters speech one stops the Prana and the apana. That which is speech is the Rig. Therefore when a man utters a Rig he neither breathes out nor breathes in. That which is the Rig is the Sama. Thus, when a man sings a Sama, he neither breathes out nor breathes in. That which is the Sama is the Udgitha. Therefore when a man sings the Udgitha he neither breathes out nor breathes in. Several other works also which require strength, such as the production of fire by friction, running a coarse, or stringing a strong bow, are performed without reference to inspiration or respiration therefore is the Vyana worshipped as the Udgitha.
One should meditate on the letters of the word Udgitha i.e. ut, gi and tha. Ut is the Prana, for men attain the power of rising from respiration. Gi is speech, for speeches are called girah. Tha is food, for all is supported by food. Ut is heaven, gi the mid region and tha the earth. Ut is the sun, gi the air and tha fire. Ut is the Sama Veda, gi the Yajur Veda and tha the Rig Veda. A person who is, thus, aware of this and adores the letters of the Udgitha as the Udgitha, speech itself yields its wealth, and the adorer obtains alimental treasure and the power to consume the same.
The 2nd khanda next explains about the fulfilment of prayers. One should thus, meditate on the objects worthy of meditation and adoration. The udgatri priest should meditate on the Sama with which he is going chant the praise. The udgatri priest must meditate on the Rig in which the Sama hymn occurs, the Sages who first promulgated them and on the deity whom he is going to praise. The udgatri priest must meditate on the metre in which he is going to chant the praise; he should also meditate on the hymn with the help of which he would chant the praise. The priest must also reflect upon the quarter of space facing which he is going to chant the praise. Lastly, the udgatri priest should meditate on himself and then on the object he desires. He must chant the praise in a proper way. Doing this he would quickly fulfil all his desires.
