Expansion and elaboration of Japji Sahib is the entire Guru Granth Sahib. Japji Sahib is the first composition of Guru Nanak, and is considered the comprehensive essence of Sikhism.

The 38 stanzas are in different poetic meters. It begins with Mool Mantra and then follow 38 paudis (stanzas) and completed with a final Salok by Guru Angad at the end of this composition. It was composed by Guru Angad, and is mostly the writings of Guru Nanak. ( Punjabi: ਜਪੁਜੀ ਸਾਹਿਬ, pronunciation: ) is the Sikh thesis, that appears at the beginning of the Guru Granth Sahib – the scripture of the Sikhs.