The Sunnah of the fitrah and what is prescribed in it

Question:
May Allah reward you with good, and may He do you good. Is it true that if a person trims his nails on Friday, no harm will befall him until the following Friday?

Answer:
Trimming the mustache, attending to the armpits and the pubic area is required, and it is among the characteristics of the fitrah. If one does this every Friday, that is better. If he delays it, there is no harm, but on the condition that it does not exceed forty days. One should not delay taking care of these things for more than forty days. This is because Anas (may Allah be pleased with him) said that the Prophet (peace and blessings be upon him) stood before us regarding trimming the mustache and cutting the nails, saying that it should not exceed forty days, or as it was reported from him. So, the conclusion is that taking care of these things every week is better. If he delays it, there is no harm, but it should not exceed forty days. Taking care of these five matters is among the characteristics of the fitrah, as the Prophet (peace and blessings be upon him) informed us: trimming the mustache, letting the beard grow, plucking the armpit hair, cutting the nails, and shaving the pubic hair. These are among the characteristics of the fitrah. Yes.