Paying tributes to the Hindu holy city's secular ethos, Modi said he wanted to see Varanasi become an internationally known spiritual capital.
"Nobody told me to come here, nobody sent me (to Varanasi)," he said, shortly before filing his nomination papers for the Lok Sabha battle here in Uttar Pradesh.
"Mother Ganga has invited me... May she bless me. May God give me strength to serve (Varanasi's) Ganga-Yamuna tehzeeb."
He pointed out how he had helped Gujarat's Muslim kite makers to improve their lot and said he would do the same for the Muslim weavers of Varanasi with modern technology, branding, designing and marketing.
He also pledged to clean up the Ganges, as he had done with the Sabarmati river in Gujarat.
"I thank the people of Varanasi for giving me so much love," he said, at the end of a roadshow that drew tens of thousands in the city.