Once there was a thug named Sheikh Sajjan. He would appear to be a nobleman but would rob people deceitfully. He pretended to be kind, God-fearing and hospitable - he would offer food and shelter to the visitors and in the stealth of night would kill them, and take away their valuables.

Once Guru Nanak, along with a Muslim companion Mardana, stayed at Sajjan's rest house. It was almost midnight and despite waiting long for his guests to fall asleep, Sajjan continued to hear the soothing sounds of bani played on the Rabab. Guru Nanak recited a hymn: "Bronze is very bright to look at; but if you keep it, your hands get blackened with it. Similarly, some people appear to be good, but they are like a house whitened on the outside, but empty within. A man should be good from inside as well as outside." Sajjan was overwhelmed and falling at the Guru's feet, confessed his crimes.

Sajjan distributed all his possessions and converted his house into a Dharamshala which, according to puratan janamsakhi, was the first such centre in the history of early Sikhism.