How authentic is the Hadith: "Do not feign illness, lest you become ill, and do not dig your own graves, lest you die"? And what is the ruling on an employee feigning illness to take what is not rightfully theirs?

The hadith: "(Do not feign illness lest you fall ill, and do not dig your graves lest you die)" is not authentically attributed to the Prophet, peace and blessings be upon him. Imam Abu Hatim al-Razi described it as a munkar (denounced) hadith, and al-Sakhawi stated that it is not authentic. Sheikh al-Albani also mentioned that it is munkar. The reason for its weakness is that one of its narrators, Muhammad ibn Sulaiman, is unknown.

Feigning illness (al-tamārud) is pretending to be sick. It is a lie to people and a practical hypocrisy that a Muslim is not permitted to do. Its impermissibility becomes more severe if a person pretends to be ill to obtain something he does not deserve, such as holidays or compensations.