Arvind ji
This very shabad of Bhagat Trilochan is the one always posted when the discussion of reincarnation/transmigration gets hot and heavy. Often people will react, “That seals it for me! There can be no debate; Gurbani supports reincarnation!”
I was once threatened on this very forum that I would return as a pig, using the exact same shabad, based on the poster's assessment of my misdeeds and shortcomings.
Just above the posted shabad Bhagat Trilochan however says something very interesting. He speaks directly to Jai Chand: abandon those yogic rituals. The matter of reincarnation is based on such rituals. It was believed that these rituals advanced one through the cycles of life and death... improved our odds of making progress so to speak. Bhagat ji is suggesting to Jai Chand, and indirectly to us, that there are better choices we can make to alter our ultimate destiny.
Also, Bhagat ji describes the 8.4 million not as life-times but life-forms
Ang 526
ਭਰਮੇ ਭੂਲੀ ਰੇ ਜੈ ਚੰਦਾ ॥
Bẖarme bẖūlī re jai cẖanḏā.
Deluded by doubt, O Jai Chand,
ਨਹੀ ਨਹੀ ਚੀਨ੍ਹ੍ਹਿਆ ਪਰਮਾਨੰਦਾ ॥੧॥ ਰਹਾਉ ॥
Nahī nahī cẖīnĥi▫ā parmānanḏā. ||1|| rahā▫o.
you have not realized the Lord, the embodiment of supreme bliss. ||1||Pause||
and then a few lines later, Guru ji says, spend the time you have in this life this way.
ਲਖ ਚਉਰਾਸੀਹ ਜਿਨ੍ਹ੍ਹਿ ਉਪਾਈ ਸੋ ਸਿਮਰਹੁ ਨਿਰਬਾਣੀ ॥੩॥
Lakh cẖa▫orāsīh jiniĥ upā▫ī so simrahu nirbāṇī. ||3||
Meditate on the Lord of Nirvaanaa, who has created the 8.4 million species of beings. ||3|
So why conclude that the bani of Bhagat ji teaches reincarnation? What evidence would Bhagat ji have for that? Would he be so much the fool to make claims without knowing for sure? Until someone dies, how does one know?
And, you are right! We do not have to talk about this in terms of “mainstream” or vedic influences or even think of goblins and pigs as metaphors.
Now you suggest we should stick to Sri Guru Granth Sahib Ji. That is a good idea. Here Guru Angad explains a few things. (Ang 1243)
ਸਲੋਕ ਮਃ ੨ ॥
Salok mėhlā 2.
Shalok, Second Mehl:
ਕਥਾ ਕਹਾਣੀ ਬੇਦੀ ਆਣੀ ਪਾਪੁ ਪੁੰਨੁ ਬੀਚਾਰੁ ॥
Kathā kahāṇī beḏīʼn āṇī pāp punn bīcẖār.
The Vedas bring forth stories and legends, and thoughts of vice and virtue.
ਦੇ ਦੇ ਲੈਣਾ ਲੈ ਲੈ ਦੇਣਾ ਨਰਕਿ ਸੁਰਗਿ ਅਵਤਾਰ ॥
Ḏe ḏe laiṇā lai lai ḏeṇā narak surag avṯār.
What is given, they receive, and what is received, they give. They are reincarnated in heaven and hell.
ਉਤਮ ਮਧਿਮ ਜਾਤੀਂ ਜਿਨਸੀ ਭਰਮਿ ਭਵੈ ਸੰਸਾਰੁ ॥
Uṯam maḏẖim jāṯīʼn jinsī bẖaram bẖavai sansār.
High and low, social class and status - the world wanders lost in superstition.
ਅੰਮ੍ਰਿਤ ਬਾਣੀ ਤਤੁ ਵਖਾਣੀ ਗਿਆਨ ਧਿਆਨ ਵਿਚਿ ਆਈ ॥
Amriṯ baṇī ṯaṯ vakẖāṇī gi▫ān ḏẖi▫ān vicẖ ā▫ī.
The Ambrosial Word of Gurbani proclaims the essence of reality. Spiritual wisdom and meditation are contained within it.
ਗੁਰਮੁਖਿ ਆਖੀ ਗੁਰਮੁਖਿ ਜਾਤੀ ਸੁਰਤੀ ਕਰਮਿ ਧਿਆਈ ॥
Gurmukẖ ākẖī gurmukẖ jāṯī surṯīʼn karam ḏẖi▫ā▫ī.
The Gurmukhs chant it, and the Gurmukhs realize it. Intuitively aware, they meditate on it.
ਹੁਕਮੁ ਸਾਜਿ ਹੁਕਮੈ ਵਿਚਿ ਰਖੈ ਹੁਕਮੈ ਅੰਦਰਿ ਵੇਖੈ ॥
Hukam sāj hukmai vicẖ rakẖai hukmai anḏar vekẖai.
By the Hukam of His Command, He formed the Universe, and in His Hukam, He keeps it. By His Hukam, He keeps it under His Gaze.
ਨਾਨਕ ਅਗਹੁ ਹਉਮੈ ਤੁਟੈ ਤਾਂ ਕੋ ਲਿਖੀਐ ਲੇਖੈ ॥੧॥
Nānak agahu ha▫umai ṯutai ṯāʼn ko likī▫ai lekẖai. ||1||
O Nanak, if the mortal shatters his ego before he departs, as it is pre-ordained, then he is approved. ||1||
The shabad of Trilochan ji needs close study, more than I have given. What bharam, untrustworthy ideas, i.e., superstitions, might Guru Angad ji be talking about? Returning as a serpent, or a prostitute, or a pig, or a goblin? We do have a clear idea from Guru Angad ji that "if the mortal shatters his ego before he departs, as it is pre-ordained, then he is approved." Why be frightened? What else than this is important?