Does an ordinary disease constitute an excuse for not offering Salah (Prayer) in congregation?
A disease that constitutes an excuse for not offering Salah in congregation is the sort of disease that may make it difficult and inconvenient for one who is ill to go to the Masjid (mosque). Evidence can be found in the Hadith of the Prophet (peace be upon him) that reads:
Whoever hears the Adhan (call to Prayer) and is not prevented by some excuse to respond to it, his Salah (at home) will not be accepted.
Ibn `Abbas (may Allah be pleased with them both) about what a valid excuse is and he said: "Fear or illness." Related by
Ibn Hibban and
Al-Hakim through an authentic Isnad (chain of narrators). The Prophet (peace be upon him)
became sick and when his disease became aggravated, he said: "Tell
Abu Bakr to lead the Salah."
(Agreed upon by Al-Bukhari and Muslim). (Part No. 7; Page No. 8) May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.