Why is Guru Gobind Singh Ji's bani not in SGGS Ji?
It is., as part of dialogue between him, his dad and the Kashmiri folks, at the crucial juncture:
SGGS Salok Mahala 9 and 10
Proper Interpretation of SGGS Verses of Salok Mahala 9 and 10
Bal chutkyo bandhan pare, kachu na hot upaye
Guru Teghbahadurji is encouraging Kashmiri Pandits, to recite with him, at the feet of Lord, making supplication of their condition
Kaho Nanak ab aut Har, gaj jo hoye sahaye
O Lord, now You only can save us
Bal Hoya bandhan chute, sab kuch hot upaye
Guru Gobind intercedes, after a period of silent meditation, that realize, God is with us and everything will be taken care of
Nanak sab kich tumahre hath mein, tum hi hot sahaye
Says Nanak, surrender to Lord is the only permanent shelter