The actor made a brief appearance at his friend Ram Lakhan's son's wedding to bless the newlyweds.
Khan told DNA India: "This is the wedding of my friend Ramlakhan Paswan's son. I have not come here to promote any upcoming serial or movie.
"I am here to attend the ceremony. I met Ram Lakhan during the promotion of 3 Idiots and he came to my house to invite me for the wedding one year ago. I wish the bride and groom the very best. Especially the bride, who may find happiness.
"Varanasi is my mother's birthplace. The place is dear to me and I share a special relationship with it."
The veteran star recently described his documentary series Satyamev Jayate as his "most ambitious project yet".
Satyamev Jayate follows 13 ordinary members of the public and tells the stories of their lives.
Khan's filmmaker wife Kiran Rao said this week that she cannot wait until the show is over.