Does Sri Guru Granth Sahib claim to be a revelation direct from God?

Sri Guru Granth Sahib Ji is a Divinely Revealed Scripture. There are many occasions when this is made clear in Sri Guru Granth Sahib Ji:

ਜੈਸੀ ਮੈ ਆਵੈ ਖਸਮ ਕੀ ਬਾਣੀ ਤੈਸੜਾ ਕਰੀ ਗਿਆਨੁ ਵੇ ਲਾਲੋ ॥
“O (Bhai) Lalo! As the Lord’s word comes to me so I deliver it.”
(Ang 722)

Gurbaani has been revealed by Vaheguru through the human living Gurus. Vaheguru spoke through Guru Nanak Sahib Ji. Even Guru Nanak Sahib Ji states that his Guru is the ‘Shabad’, the Divine Word. Guru Ji says:

ਸਬਦੁ ਗੁਰੂ ਸੁਰਤਿ ਧੁਨਿ ਚੇਲਾ ॥
“The Divine Word is the Guru, and my mind in reflective meditation, the disciple”
(Ang 943)

Guru Amar Daas Sahib Ji, the Third Nanak, goes one step forward in describing Gurbaani, the Shabad, the Divine Word, as the embodiment of the Truth, the embodiment of Vaheguru (the wondrous Lord) Himself:

ਵਾਹੁ ਵਾਹੁ ਬਾਣੀ ਨਿਰੰਕਾਰ ਹੈ ਤਿਸੁ ਜੇਵਡੁ ਅਵਰੁ ਨ ਕੋਇ ॥
“Hail, Hail, the Word of the Guru, which is the embodiment of the Formless Lord Himself; there is none other, nothing else to be reckoned equal to it.”
(Ang 515)

ਸਤਿਗੁਰ ਕੀ ਬਾਣੀ ਸਤਿ ਸਤਿ ਕਰਿ ਜਾਣਹੁ ਗੁਰਸਿਖਹੁ ਹਰਿ ਕਰਤਾ ਆਪਿ ਮੁਹਹੁ ਕਢਾਏ ॥
“O Gursikhs! Know that the Baani, the Word of the True Guru, is true, absolutely true. The Creator Lord Himself causes the Guru to chant it.”
(Ang 308)

Where there is the Word of God, there is God Himself. Where is there is the Truth, there the True One pervades:

ਸਚ ਖੰਡਿ ਵਸੈ ਨਿਰੰਕਾਰੁ ॥
“In the realm of truth (where truth pervades), there pervades the Formless Lord.”
(Japji Sahib, Ang 8 )

Guru Arjan Dev Sahib Ji, the Fifth Nanak, reiterates the message of the First Nanak that whatever is written in Gurbaani, the message of the Shabad Guru, is not from the Guru himself but it is direct from Vaheguru:

ਹਉ ਆਪਹੁ ਬੋਲਿ ਨ ਜਾਣਦਾ ਮੈ ਕਹਿਆ ਸਭੁ ਹੁਕਮਾਉ ਜੀਉ ॥
“I myself know not what to say; all I speak is what the Lord commands.”
(Ang 763)

Through Gurbaani, the Shabad, the Divine Word, Vaheguru speaks to us. The Formless Vaheguru communicated to the world through speaking through the Ten bodies of Guru Nanak Sahib Ji. Now the Formless communicates to us through the Written Divine Word. The Guru is the embodiment of Vaheguru Himself.
If we still have doubt whether Sri Guru Granth Sahib jee is just a mere “Holy Book”, then Guru Arjan Sahib Ji’s voice speaks to us through Sri Guru Granth Sahib Ji and says:

ਪੋਥੀ ਪਰਮੇਸਰ ਕਾ ਥਾਨੁ ॥
“The Divine Scripture (Sri Granth Sahib) is the meeting place where one can meet the Transcendent Lord God.”
(Ang 1226)

The Guru is saying that it is not just a “book”, but recognises it as the “meeting place to meet the Transcendent Lord God”.