Actually, they are established from Hadith. There's a famous Hadith in which 4 things to be done in great abundance in Ramadhan, "two which please Allah and two which you cannot do without" Two which please: 1. read kalimah 2. seek forgiveness from Allah Two which you can't do without: 3. ask Allah for entry into Jannah 4. seek protection from Allah So the first one above is basically the most simple formula of the above 4. The next three du'as are based on the hadith of the three 'ashara in Ramadhan - first 10 days of Rahma, second ten of Maghfirah and third ten of salvation ('itq min an-naar)... so they are just asking Allah for Mercy in first 10 days, for forgiveness in middle 10, and salvation in last 10.. Edit: there is no du'a for salvation from hell fire mentioned in OP for last 10 days. One masnoon du'a is Allahumma ajirnaa min an-Naar (O Allah save us from the Fire) The last du'a is extremely famous, and should be read especially when seeking laylatul qadr in last ten nights. to OP for the reminder.