Allah Humma Rabba Shahre RamadhanAl-Kafami, in al-Balad al-Amin and al-Misbah has quoted the Kitab al-Ikhtiyar of Sayyid ibn Baqi that if one recites the following supplication everyday in Ramazan, Allah (swt) will forgive the sins of forty years of his age.
اللّهُمّ رَبّ شَهْرِ رَمَضَانَ
O Allah: the Lord of the month of Ramadhan,
الّذِي أَنْزَلْتَ فِيهِ القُرْآنَ،
In which You revealed the Qur'an,
وَافْتَرَضْتَ عَلَى عِبَادِكَ فِيهِ الصّيَامَ،
And You imposed fasting on Your servants:
ارْزُقْنِي حَجّ بَيْتِكَ الحَرَامِ
(Please) confer upon me with the pilgrimage to Your Holy House,
فِي هذَا العَامِ وَفِي كُلّ عَامٍ،
In this year and every year,
وَاغْفِرْ لِيَ الذّنُوبَ العِظَامَ
And forgive my serious sins,
فَإنّهُ لا يَغْفِرُهَا غَيْرُكَ
For none can forgive them save You,
يَا ذَا الجَلالِ وَالإكْرَامِ.
O the Lord of majesty and honor.
