Jaap Sahib is a composition of 199 verses attributed to Guru Gobind Singh Ji, in the Dasam Granth, recited in the morning nitnem after the Japji.
It is a litany of attributes, almost entirely in the negative and the absolute: without form, without caste, without lineage, without enemy, indestructible, unbreakable. It names no incarnation and tells no story.
It draws on Sanskrit, Persian, Arabic and Braj vocabulary and it moves through several metres at speed. Recited properly it has a driving rhythm quite unlike the Japji, which is why it is sung at military and ceremonial occasions.
Its five opening verses are recited during the preparation of amrit.
The Jaap and the Japji are formally parallel and completely different in method: one argues, the other enumerates.
The composition is in the Dasam Granth and is recited daily as part of the nitnem and during the preparation of amrit. Its metres change through the text, and the effect in recitation is closer to a drum pattern than to the flowing metre of the Japji.
The vocabulary is drawn deliberately from four languages and the divine names used include Persian and Arabic forms alongside Sanskrit ones. The argument the text makes by doing that is that no tradition holds the name.
The greater part of it is negative: without form, without caste, without colour, without lineage, without enemy, without friend. What it establishes is what cannot be said, and the recitation is the practice rather than the conclusion.