A larger segment of the shabad:
ਸਿਰੀਰਾਗੁ ਮਹਲਾ ੩ ॥
सिरीरागु महला ३ ॥
Sirīrāg mėhlā 3.
Sri Rag, Third Guru.
ਹਰਿ ਜੀ ਸਚਾ ਸਚੁ ਤੂ ਸਭੁ ਕਿਛੁ ਤੇਰੈ ਚੀਰੈ ॥
हरि जी सचा सचु तू सभु किछु तेरै चीरै ॥
Har jī sacẖā sacẖ ṯū sabẖ kicẖẖ ṯerai cẖīrai.
My adorable God, Thou art the Truest of the true. Every one is in Thy power.
ਲਖ ਚਉਰਾਸੀਹ ਤਰਸਦੇ ਫਿਰੇ ਬਿਨੁ ਗੁਰ ਭੇਟੇ ਪੀਰੈ ॥
लख चउरासीह तरसदे फिरे बिनु गुर भेटे पीरै ॥
Lakẖ cẖa▫orāsīh ṯarasḏe fire bin gur bẖete pīrai.
Without meeting Guru, the spiritual guide, the mortals tantalizingly wander about in eighty four lakhs of existences.
ਹਰਿ ਜੀਉ ਬਖਸੇ ਬਖਸਿ ਲਏ ਸੂਖ ਸਦਾ ਸਰੀਰੈ ॥
हरि जीउ बखसे बखसि लए सूख सदा सरीरै ॥
Har jī▫o bakẖse bakẖas la▫e sūkẖ saḏā sarīrai.
If Reverend God forgives and grants pardon, the human body then ever remains in peace.
ਗੁਰ ਪਰਸਾਦੀ ਸੇਵ ਕਰੀ ਸਚੁ ਗਹਿਰ ਗੰਭੀਰੈ ॥੧॥
गुर परसादी सेव करी सचु गहिर ग्मभीरै ॥१॥
Gur parsādī sev karī sacẖ gahir gambẖīrai. ||1||
By Guru's grace, I perform the service of the True profound and unfathomable Lord.
ਮਨ ਮੇਰੇ ਨਾਮਿ ਰਤੇ ਸੁਖੁ ਹੋਇ ॥
मन मेरे नामि रते सुखु होइ ॥
Man mere nām raṯe sukẖ ho▫e.
O my Soul! by being imbued with the Name thou shalt procure peace.
ਗੁਰਮਤੀ ਨਾਮੁ ਸਲਾਹੀਐ ਦੂਜਾ ਅਵਰੁ ਨ ਕੋਇ ॥੧॥ ਰਹਾਉ ॥
गुरमती नामु सलाहीऐ दूजा अवरु न कोइ ॥१॥ रहाउ ॥
Gurmaṯī nām salāhī▫ai ḏūjā avar na ko▫e. ||1|| rahā▫o.
Under Guru's guidance praise the Lord's Name, (for) there is no other second than He. Pause.
ਧਰਮ ਰਾਇ ਨੋ ਹੁਕਮੁ ਹੈ ਬਹਿ ਸਚਾ ਧਰਮੁ ਬੀਚਾਰਿ ॥
धरम राइ नो हुकमु है बहि सचा धरमु बीचारि ॥
Ḏẖaram rā▫e no hukam hai bahi sacẖā ḏẖaram bīcẖār.
The Righteous Judge is under command to sit and administer even-handed justice.
ਦੂਜੈ ਭਾਇ ਦੁਸਟੁ ਆਤਮਾ ਓਹੁ ਤੇਰੀ ਸਰਕਾਰ ॥
दूजै भाइ दुसटु आतमा ओहु तेरी सरकार ॥
Ḏūjai bẖā▫e ḏusat āṯmā oh ṯerī sarkār.
The evil souls with love for duality; they are thine subjects.
ਅਧਿਆਤਮੀ ਹਰਿ ਗੁਣ ਤਾਸੁ ਮਨਿ ਜਪਹਿ ਏਕੁ ਮੁਰਾਰਿ ॥
अधिआतमी हरि गुण तासु मनि जपहि एकु मुरारि ॥
Aḏẖi▫āṯmī har guṇ ṯās man jāpėh ek murār.
God, the Treasure of excellences abides within the heart of the spiritual wayfarers and they meditate on One Lord the enemy of ego.9
First of all, when Guruji says, Ḏūjai bẖā▫e ḏusat āṯmā oh ṯerī sarkār.
The evil souls with love for duality; they are thine subjects.
Who is "thine?" "Thine" is refering to "Oh my soul!" This shabad is about bringing evil souls into alignment, into balance, away from their love of imbalance that comes from egoism and love of duality. The judge of dharma is under the hukam of Waheguru (who is dharma) to judge, to make an assessment. The assessment questions: Where are the spiritual wayfarers in a state of ego, duality? Where are the wayfarers who have found the treasure of excellence? In the rehao line we learn how to find the treasure of excellence. All the lines that follow the rehao describe the states of duality versus bliss. The shabad deserves more attention than I have given it. But it is important not to think that the judge of dharma is conducting some sort of celestial judgement in the Christian sense which is similar to the judgement made of souls who wish to enter heaven.
Now here is the second part of the shabad, on Ang 39.
The cost to those who do not find the treasure of excellence is to wander around like a lunatic. But it is not the judge of dharma who casts them into the darkness, into lunacy. They/we do this to ourselves easily enough, and do not require any assistance, it would appear. It happens when we are simply out of balance with the divine.
ਤਿਨ ਕੀ ਸੇਵਾ ਧਰਮ ਰਾਇ ਕਰੈ ਧੰਨੁ ਸਵਾਰਣਹਾਰੁ ॥੨॥
तिन की सेवा धरम राइ करै धंनु सवारणहारु ॥२॥
Ŧin kī sevā ḏẖaram rā▫e karai ḏẖan savāraṇhār. ||2||
The Righteous Judge does their service. Felicitous is the Lord who adorns them.
ਮਨ ਕੇ ਬਿਕਾਰ ਮਨਹਿ ਤਜੈ ਮਨਿ ਚੂਕੈ ਮੋਹੁ ਅਭਿਮਾਨੁ ॥
मन के बिकार मनहि तजै मनि चूकै मोहु अभिमानु ॥
Man ke bikār manėh ṯajai man cẖūkai moh abẖimān.
If man sheds his mind's evils in the mind itself and banishes from it worldly love and self conceit,
ਆਤਮ ਰਾਮੁ ਪਛਾਣਿਆ ਸਹਜੇ ਨਾਮਿ ਸਮਾਨੁ ॥
आतम रामु पछाणिआ सहजे नामि समानु ॥
Āṯam rām pacẖẖāṇi▫ā sėhje nām samān.
then does he come to recognise the Pervading Soul and easily gets absorbed in the Lord's name.
ਬਿਨੁ ਸਤਿਗੁਰ ਮੁਕਤਿ ਨ ਪਾਈਐ ਮਨਮੁਖਿ ਫਿਰੈ ਦਿਵਾਨੁ ॥
बिनु सतिगुर मुकति न पाईऐ मनमुखि फिरै दिवानु ॥
Bin saṯgur mukaṯ na pā▫ī▫ai manmukẖ firai ḏivān.
Without the True Guru, and apostate obtains not salvation and wanders about like a lunatic.
ਸਬਦੁ ਨ ਚੀਨੈ ਕਥਨੀ ਬਦਨੀ ਕਰੇ ਬਿਖਿਆ ਮਾਹਿ ਸਮਾਨੁ ॥੩॥
सबदु न चीनै कथनी बदनी करे बिखिआ माहि समानु ॥३॥
Sabaḏ na cẖīnai kathnī baḏnī kare bikẖi▫ā māhi samān. ||3||
He reflects not on the Word but utters mere words from mouth and is engrossed in sins.
ਸਭੁ ਕਿਛੁ ਆਪੇ ਆਪਿ ਹੈ ਦੂਜਾ ਅਵਰੁ ਨ ਕੋਇ ॥
सभु किछु आपे आपि है दूजा अवरु न कोइ ॥
Sabẖ kicẖẖ āpe āp hai ḏūjā avar na ko▫e.
Everything the Lord Himself is. There is no other second.
ਜਿਉ ਬੋਲਾਏ ਤਿਉ ਬੋਲੀਐ ਜਾ ਆਪਿ ਬੁਲਾਏ ਸੋਇ ॥
जिउ बोलाए तिउ बोलीऐ जा आपि बुलाए सोइ ॥
Ji▫o bolā▫e ṯi▫o bolī▫ai jā āp bulā▫e so▫e.
When that Lord Himself causes us to speak, we speak just as He wants us to speak.
ਗੁਰਮੁਖਿ ਬਾਣੀ ਬ੍ਰਹਮੁ ਹੈ ਸਬਦਿ ਮਿਲਾਵਾ ਹੋਇ ॥
गुरमुखि बाणी ब्रहमु है सबदि मिलावा होइ ॥
Gurmukẖ baṇī barahm hai sabaḏ milāvā ho▫e.
The Exalted Guru's Word is God Himself and it is through Word that man obtains union with God.
ਨਾਨਕ ਨਾਮੁ ਸਮਾਲਿ ਤੂ ਜਿਤੁ ਸੇਵਿਐ ਸੁਖੁ ਹੋਇ ॥੪॥੩੦॥੬੩॥
नानक नामु समालि तू जितु सेविऐ सुखु होइ ॥४॥३०॥६३॥
Nānak nām samāl ṯū jiṯ sevi▫ai sukẖ ho▫e. ||4||30||63||
O Guru Nanak! Remember thee God's Name, by serving whom, thou shalt obtain peace.
This part explains what the judge of dharma is to do, with the mercy and kindness of the almighty. I am going to oversimplify and say that the judge of dharma is the servant of the spiritual wayfarers who have enshrined the Treasure of the Lord's name in their hearts. In other words, these are the souls that have found balance, equipoise, alignment in dharma, oneness with the creator who is dharma.