This is an interpretative commentary on "Asa Di Var" a prominent verse of Guru Nanak written in Indian classical measure called "Raag Asa." The word "Var" in the ordinary sense is a heroic ballad sung in praise of the heroic deeds of a great warrior. It has a predominance of war imagery, and martial times. But in this verse, Guru Nanak has shifted the focus from a physical battle scene to a spiritual voyage and its protagonist from a traditional military warrior to a common human being. Life's whole journey is conceived in terms of an inner spiritual battle between man and human vices. His struggle and victory over vices is celebrated in this verse. This explanation and interpretation of this lengthy verse in English is indeed a monumental task. The learned author, being well versed both in his native Punjabi as well as proficient in his self-acquired knowledge of English, has succeeded in revealing the full extent of Sikh Guru's spiritual vision to a vast section of non-Punjabi Eastern and western readership. In between, he has also stated the fundamental postulates of Sikh Theology, Sikh ideology and Sikh way of life through illustrations from this verse.