Arafa Ke Din Ka Roza 2 Saal Ke Gunaahon Ki Maghfirat
Abu Qatada al-Ansari r.a se marvi hai k unhone ne Allah k Rasul sallellahu alayhiwasallam se Arafa k roze ka pucha to k Rasul sallellahu alayhiwasallam ne farmaya Arafa k din ka roza aisa hai k main umeedwaar hun Allah tala se k ek saaal agle aur ek saal pichle gunahon ka kuffara hojaye
Sahih muslim, roze k masail (Kitab Al-Sawm) no: 2746 & 2747
Abu Qatada al-Ansari (Allah be pleased with him) reported that the Messenger of Allah (may peace be upon him) was asked about fasting on the day of 'Arafa (9th of Dhu'I-Hijja), whereupon he said: It expiates the sins of the preceding year and the coming year.
Sahih muslim, The Book of Fasting (Kitab Al-Sawm)
http://www.tafrehmela.com/islamic-question-answer/134319-ahaadees-its-discussion-5.html#post883755