1000 days of prayer sawab (dua)
Holy Prophet Mohammed (Sallallaho Alaihi Wa’Sallam) has said, that whoever recites this dua even if 1 time, he/she will get such a huge reward/sawab that 70 angels/farishte will continously write its reward/sawab for 1000 days.
If it is recited in Ramadan even only 1 time then also 70 angels will continously write its reward for 70,000 days (70 times) means 192 years.
If one recites only 100 times in Ramadan then 70 angels will continously write its reward/sawab for 19128 years.
(Hadith Book : Al-Tabarani)