Silsilah Sahihah

It is narrated from Sayyiduna Abu Hurairah (may Allah be pleased with him) that the Messenger of Allah (peace and blessings of Allah be upon him) said: "Every inhabitant of Hell will see his place in Paradise and will say: 'Alas! If only Allah had guided me (then that place would have been my abode).' This will become a cause of regret and remorse for him. And every inhabitant of Paradise will see his place in Hell and will say: 'If Allah had not guided me (then that place would have been my abode).' This will become a cause for him to thank Allah Almighty." Then the Messenger of Allah (peace and blessings of Allah be upon him) recited this verse: «أَنْ تَقُولَ نَفْسٌ يَا حَسْرَتَى عَلَى مَا فَرَّطْتُ فِي جَنْبِ اللَّـهِ» (39-az-Zumar:56) "(Lest) a soul should say: 'Alas, my grief that I neglected the duty to Allah and I was indeed among those who mocked.'"