There are 88 ayaat in Surah al-Qasas and it was revealed in Makkah though some scholars say that it was revealed in Madinah. The 58th verse of this surah was revealed at the time of the Holy Prophet’s (s.a.w.) migration from Makkah to Madinah.
It is narrated from the Holy Prophet (s.a.w.) that whoever recites this surah will get the reward equivalent to the number of people present at the time of Prophet Musa (a.s.) and all the angels will bear witness on his behalf.
If one drinks the water in which this surah has been dissolved, all his problems and worries will, Insha-Allah, be solved.
Imam Ja’far as-Sadiq (a.s.) has said that drinking water in which this surah has been dissolved is a remedy from illness and worrie.