Sankaracarya's Vivekachudamani 490

असङ्गोऽहमनङ्गोऽहमलिङ्गोऽहमभङ्गुरः ।

प्रशान्तोऽहमनन्तोऽहममलोऽहं चिरन्तनः ॥

asaṅgo'hamanaṅgo'hamaliṅgo'hamabhaṅguraḥ |

praśānto'hamananto'hamamalo'haṃ cirantanaḥ ||

(Sankaracarya's Vivekachudamani 490)

Unattached am I, disembodied am I, free from the subtle body am I and undecaying; serene am I, Infinite am I, unsullied am I, and endless too.

Sripad Sankaracarya even while he is living in this world, he could already have the feeling of attaining liberation or moksha. In this sloka he is explaining that the word I is referring to the Atma.

His Atma is not attached to the material world. His Atma is separate from his body, His Atma has no subtle body, His Atma is not relying on anything in this material world, His Atma is undisturbed, His Atma is infinite, His Atma is unpolluted and His Atma has no end.