It is mentioned that when al-Hafidh Ibn Hajr was the Chief Justice (of Egypt), one day he was passing through the market with a caravan, looking well groomed. So a Jew who was selling hot oil, looking very disheveled and dirty because of the oil, accosted him by grabbing the reins of his mule saying, “Yaa Shaykhul-Islaam, you claim that your Prophet said that the dunyaa is a prison for the mu’min and a jannah for the kaafir; so what type of prison are you in and what type of jannah am I in?”

He (Ibn Hajr) replied, “Regarding what Allaah has prepared for me in the hereafter from its bliss, then it is as if I am in prison, and with regards to what Allaah has prepared for you in the hereafter from its punishment, then it is as if you are in jannah.”

At which point the Jew became a Muslim.

 
(Faydhul-Qadeer: 3/546)