Holy Dialogue (Pravachana Vakhyalu):
April 28, 2014: Om is imperishable. All names in this world is perishable, for it goes with the corresponding form. But this Universal Form is imperishable, this Universal Name also is imperishable, comprehends everything. Omityetadaksharam: Om is Akshara, and Akshara is imperishable. Tasyopavyakhyanam, bhutam, bhavat, bhavishyaditi sarvam Omkara eva; Yaccanyat trikalatitam tadapyomkara eva... All that was in the past, all that is now in the present, all that will be in the future, all this is Om, because Om has no past, present and future; the Universal has no .time. What a grand description of Om is given in the Mandukya Upanishad! Whatever is in time, as past, present and future, is Om. Not merely this; that which is above time, also, is Om. Om has a twofold nature, the temporal and the eternal: it is Sabda and Sabdatita. It is constituted of A, U, M, representing all creation; but it has also a fourth nature which transcends these distinctions of A, U, M. It is called Amatra and Chaturtha-Bhava: The soundless form of Om is Amatra, the immeasurable, and it is not audible to the ears. This Amatra, or the immeasurable, eternal nature of Om is not a sound or even a mere vibration, but it is just existence, pure and simple, known as Satchidananda-Svarupa - Existence-Consciousness-Bliss.
---Excerpts from Upanishads