Islam

Among the Muslim Sufis, it is known as Sultan-ul-Azkar (the king of prayers). Another order of Sufis call it Saut-i-Sarmadi, (the Divine Song). They also call it Kalam-i-qadim (the Ancient Sound), and the Kalma or Word, Nida-e-Asmani (the Sound coming down from Heaven). The fourteen Tabaqs (regions) were made by the Kalma – the Word.

Khawaja Hafiz, a great divine, says:

From the turret of the Heaven, a call bids thee Home, But fallen into the snares thou listeneth not. No one knows where the Mansion of the Beloved lies, but sure enough, the chiming of the bells proceeds therefrom. 

Again,

Take the stop-cock from thy ears, and hear thou the voice of emancipation coming to thee, Attach yourself not to the material world, the elixir of life is showering from above. The beat of Love while sounding in the Heavens, sends blessings to the souls of the devotees. 

Jalal-ud-din Rumi, in his Masnavi, says:

Grow not sceptical, but attune thyself to the Sound coming down from the Heavens, thy soul shall have revelations from afar. What are these? The glimpses of the Unrevealed; were I to speak of these sweet melodies, even the dead shall rise from their graves.