"Japji Sahib" is the first composition of Guru Nanak, and is considered the comprehensive essence of Sikhism. Expansion and elaboration of "Japji Sahib" is the entire "Guru Granth Sahib". It is first Bani in Nitnem. Notable is Nanak's discourse on 'what is true worship' and what is the nature of God'. According to Christopher Shackle, it is designed for "individual meditative recitation" and as the first item of daily devotional prayer for the devout. It is a chant found in the morning and evening prayers in Sikh gurdwaras. It is also chanted in the Sikh tradition at the Khalsa initiation ceremony and during the cremation ceremony.