 "Upadesha", "Adesha", "Abhyasa" and "Anubhava"; accordingly the "vakya" – Tat Tvam Asi, appearing in the Chandogya Upanishad, is an "Adesha Vakya", a command statement; the "shishya" or 'disciple' listens to the "Upadesha vakya" and the "Adhesha vakya" with full faith and devotion which act is called Sravana ('concentration').In the Sanskrit phrase - अथात आदेशः नेति नेति "athāta ādeśah