Qawwali singers further expand on this text by inserting additional short lyrics, often many of them, given the deep significance this particular song has for Sufis. Some singers specialize in rhythmic variety, others in melodic improvisation. The core opening statement is elaborated upon through a virtuosic range of musical variation, some of it original and some drawn from an established body of alternative tunes for the text.
The full song consists of six lines of text, but since the entire meaning is contained in the first two lines, the others are usually repeated only cursorily. Sufi tradition says that the raga has since evolved in the classical tradition while remaining preserved in its original form in qawwali. The music for this lyric, according to modern qawwali singers, is based on an archaic version of a north Indian classical music raga, Shudh-kalyan. He is also credited with creating the entire genre of qawwali that is a hallmark of South Asian Sufi ritual. According to Indian Sufis, it was first set to music by the thirteenth-century poet and musician Amir Khusraw Dihlavi (see also track 6), who elaborated upon the two lines with phrases in Persian, which today are only partly intelligible. The lyrics express a basic Sufi tenet: that the Prophet himself instituted the spiritual succession in Sufism.
At some Sufi shrines, all qawwali events begin with this famous composition at others it serves as the finale.