Ek Oankar, Sat Nam Kaarta Purakh Nirbhao Nirvair
Ajoonee Saibhan Guru Prasaad
Aadh Sach Jugaad Sach.
Hai Bhee Sach
Nanak Hosee Bhee Sach
The Mul Mantra are the words first spoken Guru Nanaak upon attaining enlightenment, and is the first verse of the Siri Guru Granth Sahib.
It should be noted, that Guru Nanaak, after attaining enlightenment, refered to God as his Guru.
So, Gur Prasaad, is by Gods Grace.