Why don't all Gursikhs recite ‘Sampuran Rehraas Sahib’?
According to the Panthic Sikh Rehit Maryada:
ਸੋ ਦਰੁ ਰਹਿਰਾਸ- ਸ਼ਾਮ ਵੇਲੇ ਸੂਰਜ ਡੁੱਬੇ ਪੜ੍ਹਨੀ। ਇਸ ਵਿਚ ਇਹ ਬਾਣੀਆਂ ਸ਼ਾਮਲ ਹਨ:-
ਸ੍ਰੀ ਗੁਰੂ ਗ੍ਰੰਥ ਸਾਹਿਬ ਜੀ ਦੇ ਵਿਚ ਲਿਖੇ ਹੋਏ ਨੌ ਸ਼ਬਦ ('ਸੋ ਦਰੁ' ਤੋਂ ਲੈ ਕੇ 'ਸਰਿਣ ਪਰੇ ਕੀ ਰਾਖਹੁ ਸਰਮਾ' ਤਕ), ਬੇਨਤੀ ਚੌਪਈ ਪਾਤਸ਼ਾਹੀ ੧੦ ('ਹਮਰੀ ਕਰੋ ਹਾਥ ਦੇ ਰੱਛਾ' ਤੋਂ ਲੈ ਕੇ 'ਦੁਸਟ ਦੋਖ ਤੇ ਲੇਹੁ ਬਚਾਈ' ਤਕ, ਸ੍ਵੈਯਾ ('ਪਾਇ ਗਹੈ ਜਬ ਤੇ ਤੁਮਰੇ') ਅਤੇ ਦੋਹਰਾ ('ਸਗਲ ਦੁਆਰ ਕਉ ਛਾਡਿ ਕੈ') ਅਨੰਦ ਦੀਆਂ ਪਿਹਲੀਆਂ ਪੰਜ ਪਉੜੀਆਂ ਤੇ ਅੰਤਲੀ ਇਕ ਪਉੜੀ', ਮੁੰਦਾਵਣੀ ਤੇ ਸਲੋਕ ਮਹਲਾ ੫ 'ਤੇਰਾ ਕੀਤਾ ਜਾਤੋ ਨਾਹੀ।'
“Sodar Rehras – should be read in the evening after sunset. This Bani comprises of the following compositions:-
Nine Shabads written in Sri Guru Granth Sahib (beginning “So Dar”, up to “saran pare ki rakho sarma"), the Benti Chaupai of the tenth Guru (beginning "hamri karo haath dai rachha" and ending with "dusht dokh te leho bachai"), Svaiyyaa ("paae gahe jab te tumre") and Dohra ("sagal duaar kau chhaad kai"), the first five and the last pauris (stanzas) of Anand Sahib, and the Munduvani & Salok Mahla 5 (“tera keeta jaato naahee".
It is inappropriate to use such terms as "sampuran" (complete) or incomplete. The standard Sodar Rehraas Sahib read at Sri Darbar Sahib is “complete” and “sampuran”.
The Chaupai Sahib read at Sri Darbar Sahib (Amritsar) during Sodar Rehraas Sahib is widely accepted in the Panth, it is also known as 'Kabiyo Baach Benti - Chaupai'. It starts from “Hamri Karo Haath Dai Raccha...." and concludes at "Dusht Dokh Tai Leho Bachaaee", the rest of the tuks pertain to the actual compilation of the Charitropakhiyan Bani/Granth ("puran kara Granth tatkala...").
Some Jathebandis (groups) read two more couplets after this, which is fine too. Some Nihang Jathas read two Chaupais in Sodar Rehras, the first one starts with "Dusht Daint Kach Baat Na Jaani || Mahakaal Tan Pun Ris Tthanee||..." In total there are 9 paurees (stanzas) in this complete Chaupai. "Pun Rachhass Ka Kaatta Seessaa.." are actually the last two paurees of this, and some Jathas only read the last two in Sodar Rehraas Sahib, some don't read them at all.
The Chaupai in Dasam Granth does not contain the Svaiyaa and Dohra we read in Sodar Rehraas Sahib. Those are verses found in other parts of the Dasam Granth.
If anyone wants to read more that is fine, but it should not be called incomplete. Otherwise the 10 svaiyaas in Nitnem would be incomplete, since they are only a small extract from the larger Bani known as Sri Akaal Ji Ki Ustat (which comprises of 33 svaiyaas), but the 10 svaiyas in Nitnem are in themselves sampuran, just like the 6 pauris of Anand Sahib read in Sodar Rehras Sahib.