Some muslims asks sikhs 'where is the proof in your holy book that it is a word of God' because they are trying to apply their religious logic on us. Sikhi is an indic faith, Shri Guru Granth Sahib is not a semitic book, we don't believe in prophets. SGGS is a word of God because you only praise God when he wants you to. These words of God give you spiritual guidance and eternal bliss not strict, unchanging social laws like Quran which are forced on believers & non-believers alike. Page 722- ਜੈਸੀ ਮੈ ਆਵੈ ਖਸਮ ਕੀ ਬਾਣੀ ਤੈਸੜਾ ਕਰੀ ਗਿਆਨੁ ਵੇ ਲਾਲੋ॥ As the Word of the Forgiving Lord comes to me, so do I express it, O Lalo. Page 763- ਹਉ ਆਪਹੁ ਬੋਲਿ ਨ ਜਾਣਦਾ ਮੈ ਕਹਿਆ ਸਭੁ ਹੁਕਮਾਉ ਜੀਉ ॥ By myself, I do not even know how to speak, I speak all that the Lord commands.