Abu Uthman Nahdi (may Allah have mercy on him) says that once I was present in the service of Hazrat Abu Huraira (may Allah be pleased with him) and I said, "I have heard that you say that for one good deed, a reward of up to one million good deeds can be given?" He replied, "Are you surprised at this? By Allah! I heard the Noble Prophet (peace and blessings be upon him) say that Allah multiplies one good deed until it becomes equal to twenty million good deeds."