The portrayal of Rānī Rāj Kaur in Rāṇā Sūrat Singh represents the zenith of Bhāī Vīr Singh's creative art and consciousness. To enter the imaginative and mystical world of Rānā Sūrat Singh is itself, in Harbans Singh's words, “to encounter the poet's mind and soul at their subtlest and most intimate.” The poem is more than twelve thousand lines long, and it is unique in Punjabi literature for its form and size as well as its artistic qualities. It was published in 1905 and instantly became a major inspiration for the other writers of the Sikh renaissance.

The epic is a vitally important statement of Sikh mysticism, for it recounts the experience entirely from a Sikh perspective. Mystical experience does, of course, have a universal core, as Evelyn Underhill brought out in her classic work on mysticism from an ecumenical perspective. For her, the intimate and passionate love for Ultimate Reality is the distinctive mark of all mystics irrespective of their racial and religious backgrounds: “There is little difference in this between the extremes of Eastern and Western thought: between A Kempis the Christian and Jalalu'd Din the Moslem saint.” If the notion of mysticism is to have any meaning, there must be some truth to this view, but it is somewhat overstated.