Abu 'Ubaidah reported from Jabir ibn Zaid that Abu Hurayra said, " The Messenger of Allah, may Allah bless him and grant him peace, said, 'He who observes fasting during Ramadan out of sincere faith, and hoping to attain Allah's rewards, then all his past sins will be forgiven. And if you would know what is in the merits of Ramadan, you would wish it lasts for a year.' "