Bismillaahi Ar-Rahmaani Ar-Raheem (in the Name of Allah, the Most Merciful, the Most Compassionate)! I once heard a story from a scholar of a righteous man who fasted for 20 years (on the days of the Sunnah) and did not tell his wife (for the purity of his intentions). Have you heard of something similar as well? If so, can you give me the reference for this please?

All perfect praise be to Allah, the Lord of the worlds. I testify that there is none worthy of worship except Allah and that Muhammad is His slave and Messenger.

May Allah have mercy upon our righteous predecessors; many of them would hide their deeds in order to achieve sincerity.

An example of this is what was reported about Dawood ibn Abi Hind and cited by Ibn Al-Jawzi in Al-Mud-hish and by Ath-Thahabi in As-Siyar, “Dawood ibn Abi Hind fasted for forty years and no one knew about it. He would take his lunch and go out to his shop, and he would give his lunch in charity on his way. The people of the market would think that he had eaten at home and his family would think that he had eaten in the market.”

Allah knows best.