It is narrated from the Prophet (saw) that it is recommended to pray this prayer on Sunday in the month of Dhul-qadah with a great reward.
That whoever prays it, his sins will be forgiven and his repentance will be accepted and Allah (swt) will make his liabilities to others cleared and when he dies he will die with faith (Iman). And his religion will be intact. His grave will be widened and enlightened, his parents will be pleased with him and Allah (swt) will forgive his parents and children and
will give him more wealth. And the Angel of Death will be gentle with him when taking his soul. And many other great benefits for this special prayer.
Reference to this salaat: Mafateeh Al Jinan by Shiek Abbas Qummi (page 247), A'maal the month of Dhul-qadah
It is recommended to pray a 4 rakat salah on any sunday in Dhul-qadah.
In every rakat:
1. Sura Alhamd once
2. Ikhlass 3 times
3. Falaq once
4. Naas once
after salaam 70 times
astagfirullaah wa rabbee wa atoobu ilayh
la hawla wala quwata illa billa hil aliyil azeem
Yaa a'zeezu yaa ghaffaarugh-fir lee d'unobee wa
d'unooba jamee-i'l moo-mineena wal moominat
fa-innahu laa yaghfirud' d'unooba illaa anta.