This is an invaluable write up by a Gurmukh on the path of surat shabad marg. Take laha and inspriation from it friends.
OUR NIJ GHAR- THE FOURTH SUNN
Our mind thinks incessantly and does not hold still even for an instant. Under all sorts of distractions it wanders aimlessly in all directions. Only after finding a perfect Guru thru good fortune, who gives mantra of Lord's Name (for japna) that mind becomes quiet and tranquil:
"Eh mun na tikay bauhrangee deh dis dhavay.
Gur poora paaia vadbhagee Har Mantar deea mun thadhay" p-171
This is what Naam Japna does to a wandering mind. It tries to make it still, till it stops thinking when it is lured into the 'dhun' of the japna and comes inside where it is totally disconnected from the input of the five sense organs. It becomes totally thoughtless, a condition called 'sunn' in Gurbani. In this condition mind stops giving any instructions to the body which becomes still and is said to be in 'smadhee'.
It is in this condition the mind is disconnected from world of Maya of three modes and comes in where Naam/ Sabad is. This space where mind comes in is called 'sunn mandal'. Gurbani mentions about sunn many a time, as location of Naam, Satguru and God. Purpose of Naam Japna is to disconnect the mind from Maya and its bad effects in Raj Gun and Tum Gun and clean it up with Naam/ Sabad :"Bhareeay matt papaan kay sung. O dhopay naavay kay rung." Sabad is God's utterance in all the bodies: "Ghat ghat vaajay naad." and cleans the dirt caused by Mayan thoughts: "Mun dhovo sabad laago Har sio raho chit laa-ay."p-919
The inner journey for spiritual development is thru sunn where Naam/Sabad Guru who is also called Satguru in Gurbani, who not only gives spiritual knowledge but also prepares the mind for meeting with Nirankar.
"Sabade he Naaon upjay sabade mail milaaia." p-646
As the mind just enters into sunn it is said to be sitting in FIRST SUNN. When the thoughtless mind in sunn merges with the ambient of the sunn mandal it adopts the nature of air there, the first creation of God, Sach:
"Saachay te pavna bhaiaa." p-19
"Suneh sunn miliaa samdarsi pavan roop ho jaae-geh." p-1103
This condition of mind in Sunn Mandal when it merges with air is called the SECOND SUNN.
Continuing progress on this journey in sunn, Anhad Sabad, the unstruck divine melodies are heard there. These are the utterances of the Nirankar inside us as Sabad Guru. It is here that mind starts getting cleansed by Sabad/ Naam to prepare for the journey to the goal. This zone in the sunn manadal is called Amritsar or Pool of ambrosial nectar of Naam where mind bathes in it to clean itself:
"Antar koohnta Amrit bharia" p-570.
This zone is also called Dev Sathan, the area where devtas, the angels live in three gunas after physical death as they did not reach the Nirankar yet:
"Dev sathany kia nissani.
Teh bajay Sabad anahad banee."p-974
Devtas are stuck here and could not go beyond for not having done enough bhagti to cross over the 'bhavjal sagar'. They don't have to be born again but can't go beyond to unite with Nirankar. And beg God to give them another chance in human body so that they can do more bhagti to crossover to higher level:
"Is dehi ko simray dev.
So dehee bhaj Har kee sev." p-1159
This state of mind surrounded by Anhad Sabad is called the THIRD SUNN. This is also called 'dhaval', a cross over between Bhavjal Sagar and Nij Ghar. Here mind is with air which it sheds before entering into the next sunn. This is also called 'dar' or doorway to the Sach Mehal/Parkash Mehal, the Mansion of the Divine. It is about this state Guru Nanak Ji is writing about in 27th Pauri of Jap Ji Sahib, describing the symphony of celestial music going on at the dar or gate of the Sach Ghar where all His creation is singing praises to Him:
"So dar keha so ghar keha jit beh sarab smaalay.
Vaajay naad anake asankha ketay vavanhaary.
Ketay raag paree sio kaheean ketay gavanharay.
Gaavay tohnau paun panee baisantar gavay raja dharan duaaray."p-6
Next step in progress comes when the mind is fully cleansed of the filth of Maya and is waiting for the Grace of God to open the Tenth Door to let His child in. This is preceded by sounding of Toor and Naad:
"Anhad Banee Naad vajaaia."p-375
As the Door opens amidst sounding of Five Sabads, mind is welcome home having conquered five doots of Maya. Mind sheds the air and is illumined with Jot of God and is fully awakened to its spiritual self by the Sabad:
"Dhun upjee Sabad jgaaia" p-1039.
Free from bondage of Maya, mind sees nothing but Parkash or Divine Light/ Jot and finally meets the Beloved Lord:
"Pargati Jot milay Ram Piaray."p-375
This happens with the Grace of the Guru that one meets the Lord, finds perfect peace and tranquility with such ease:
"Guru Nanak tutha miliaa Har Raaia.
Sukh raen vihaani sehaj subhhaia."p-375.
This is the area where dwells the perfect Lord Brahm in sunn-smadh and holds discussions with Bhagats. There is no happiness or grief and no death or birth (but absolute tranquility):
"Sun samadh gufa te asan.
Kewal Brahm pooran teh basan.
Bhagat sang Prabh gosht karat.
Taha harakh na sog na janam marat."p-894.
This is the Fourth SUNN and end of mind's journey back to its Nij Ghar and Sehaj Ghar where it can live in perfect bliss and becomes Jiwan Mukat, liberated while alive.
This sunn is also called Anhad Sunn. Those minds who reach this sunn become just like the One Who created them:
'Anahad sunn rattay se kaisay.
Jistay upjay tishee jaisay." p-943
Sunn prevails inside and outside in all three zones; earth, sky and nether-lands. In fourth sunn mind becomes Gurmukh and its karmas are over and is not judged for these:
"Antar sunan bahar sunnan tri-bhavan sunam sunan:
Chauthai sunun jo nar jaanai ta ko paap na punnan." p-943
This is the house of the True One as told by the Satguru and is also the true house of His child, mind who is on a physical journey on this planet, Earth:
"Satgur tay paa-ay veechara .
Sunn Samadh Sachay Ghar bara." p-1037
Gurbani guides us how to make it to our true home while alive and become a jeevan-mukat so that at the end of our physical life we land straight into Nijh Ghar and are met with our Father, Nirankar who greets us with a hug, congratulating us for our victory in fight with five-doots of Maya:
"Jo jan Har Prabh Har Har sarna tin dargeh Har Har deh vadiaaee.
Dhan dhan sabaas kahay harjan ko Nanak mel la-ay gal laee." p-493
Gurmukhs thus establish an easy access to Nij Ghar from Bhavjal Sagar via sunn, Anhad Sabad, Toor and back to Bhavjal Sagar for their mundane responsibilities following the same route back.
'Gurmukh aavay jaa-ay nisang." p-932