Here’s an excerpt from a lecture by Siri Singh Sahib Ji, “Mool Mantra, the Root Mantra of all Mantras”:

“The many words of Siri Guru Granth Sahib are like the leaves of a great tree. There are twenty millions and trillions of leaves on this tree, there are thousands of branches on the tree, but there is only one root. Therefore you are given a Mool Mantra, the Root Mantra of all mantras: “Ek Ong Kaar, Sat Naam, Kartaa Purakh, Nirbhau, Nirvair, Akaal Moorat, Ajoonee, Saibhang, Gur Prasaad, Jaap: Aad Sach, Jugaad Sach, Hai Bhee Sach, Naanak Hosee Bhee Sach.” What Nanak has said in these few words is a great secret to know. Nanak has explained God. What is God? Ek Ong Kaar: there is One Creator who has created this creation. Sat Naam: Truth is His Identity. Kartaa Purakh: the Being who does. Nirbhau: Fearless. Nirvair: Revengeless. He is explaining the Universe. Akaal Moorat: beyond death. Ajoonee: it doesn’t come in birth or death. Saibhang: by itself. And Gur Prasaad: it is the gift of the Guru. How is that gift obtained? Here are the orders: Jaap. What’s Jaap? Perform this meditation. Aad Sach, Jugaad Sach, Hai Bhee Sach, Naanak Hosee Bhee Sach: True in the Beginning, True in the Primeval Age, True now, says Nanak, He shall certainly be True in the future.”