Ayamatma Brahma is the Mahavakya described in the ancient Hindu scriptures and Upanishads of India, which literally means this soul is the Brahm.

The element beyond that self-illuminated visible body is propounded by the term 'Ayam'. The indirect force that keeps the body alive is the 'soul'. That soul is present in all beings in the form of Parabrahma. In the entire variable-universe world, it is enumerated in essence. He is Brahm, he is self-published 'self-realization' as self-realization.

This mantra is also Mahavakya of Badrinath Dham or Jyotirmath, which is one of the Four Dham`s of India located in the north.

What does Mahavakya mean?
If you follow this one sentence and research the ultimate state of your life, then your life will be fulfilled successfully. Therefore it is called Mahavakya.