Bebe Nanaki asked her brother, Guru Nanak Dev…

Bebe Nanaki asked her brother, Guru Nanak Dev Ji, "Brother Ji, where were you for three days?"

Guru Ji replied, "Sister Ji, I had gone to the True Realm (Sachkhand) of Nirankar."

Bebe Nanaki then asked, "What is this True Realm (Sachkhand) of Nirankar like?"

Guru Ji answered:

"Sach khandi vase Nirankar. Kari kari dekhe nadar nihal."

(In the True Realm, Nirankar resides. He beholds His creation again and again with His gracious gaze and blesses them.)

After this, Guru Ji, in a state of deep wonder, described the glory of Nirankar's divine court through the So Dar hymn in Japji Sahib and later recited the So Dar hymn in Rehraas, where he expressed the grandeur of Nirankar’s divine door in an astonishing manner.

Guru Ji stayed in Sachkhand with Nirankar for three days and returned with the Mool Mantra written below for the quick spiritual upliftment of the world:

"Ik Onkar Satnam Karta Purakh Nirbhao Nirvair Akaal Moorat Ajooni Saibhang Gur Prasad."

This Mool Mantra is the foundation of Shri Guru Nanak’s teachings and Sikhism, and upon this foundation, the grand structure of Sikhism was built.

Meaning of the Mool Mantra: ੴ (Ik Onkar): There is only one Eternal Creator (Akal Purakh). There is none like Him, and He is omnipresent.

Satnam: His name embodies eternal existence and remains forever unshakable.

Karta: He is the Creator of all.

Purakh: After creating everything, He pervades it completely.

Nirbhau: He fears no one.

Nirvair: He has no enmity with anyone.

Akaal Moorat: He is beyond time, formless, and unaffected by time.

Ajooni: He does not take birth in any life forms; He neither takes birth nor dies.

Saibhang: He is self-existent; no one created Him.

Gur Prasad: Such an Akal Purakh is attained only through the grace of the Guru.