Is it permissible for a girl to stipulate as her mahr (dowry) that her fiancé commit to performing the five daily prayers, instead of requesting gold, given that he is lax in prayer due to work, and her aim in this is to encourage him to adhere to them?

Marriage requires the existence of a dowry (mahr), which must be money or something of monetary value, based on the Almighty’s saying: (And lawful for you are [all others] beyond these, [provided] that you seek them with your properties, intending chastity, not unlawful sexual intercourse) An-Nisa/24. It is permissible for the dowry to be teaching the Qur’an or beneficial knowledge, because education is a benefit that can be valued financially, based on the hadith of the man whom the Prophet, peace and blessings be upon him, married to a woman by what he possessed of the Qur’an, stipulating that he teach her what he knew of it. However, the husband's observance of prayer cannot be a dowry. It is recommended to facilitate the dowry and not to be excessive in it. It is advisable to ask for a modest dowry and to stipulate that the husband observes prayer.