It was narrated from Shuaib bin ‘Abdullah bin ‘Amr that his father said: “The Messenger of Allah ﷺ said to me: ‘Fast one day and you will have the reward of ten.’ I said: ‘Let me fast more.’ He said: ‘Fast two days and you will have the reward of nine. I said: ‘Let me fast more than that.’ He said: ‘Fast three days and you will have the reward of eight.” (One of the narrators) Thabit said: “I mentioned that to Mutarrif and he said: ‘I only see that he is making more effort for less reward.”(Hasan)