Actually the ad granth (only 1-5 gurus writing) was stolen and the 10th Guru was asking for it to be given back. The people who stole it said if your the guru then why cannot you just write it out from memory. Then the 10th Guru wrote it all out from memory but added 9th Guru's writings in there and from then onwards it was called SGGS.
I believe the granth was stolen before 10th guru was born so if someone can confirm during which guru's time it was stolen...
I didn't know this....did she collate everything once the 10th guru had installed SGGS?
The main question I am trying to ask is why are the two granths not together as one granth.