Bismillaah Al-Hamdulillaah wa salatu wa salaamu 'ala rasulullaah
Amma ba'd
Sincerity of the Salaf
Here is an excerpt:
Also read: Scholarly Gems of Tremendous Benefit as Related to al-IkhlaasIt is mentioned in the biography of Dawud ibn Abi Hind, that he fasted for forty years and his own family did not know it. He would go out to work in the morning carrying his lunch so his family would think he was not fasting that day, and then he would give his lunch away as charity on his way to work. He would return home in the evening and eat with his family.