What is the criterion for perceiving the takbirat al-ihram – whoever perceives it for forty days shall have two immunities written for him – and if he perceives it then abandons it, do the two immunities remain for him?

Whoever consistently maintains the takbirat al-ihram for forty consecutive days will have two immunities written for him: immunity from the Fire and immunity from hypocrisy. This is based on the Prophet's (peace and blessings be upon him) saying: "Whoever prays to Allah for forty days in congregation, reaching the first takbir, two immunities will be written for him: immunity from the Fire and immunity from hypocrisy." Only he whose solace is in prayer will be granted such success.