the Friday prayer or the noon prayer. If he can perform (1) the Friday prayer, it is obligatory for him; if he cannot, he performs the noon prayer. Once the Friday prayer has been missed, he can perform the noon prayer, and therefore he is obligated to perform it. For this reason, according to most scholars, the noon prayer may not be performed unless the Friday prayer has been missed.
As for the prescribed prayer, it can under no circumstances be performed by proxy. The same applies to fasting Ramadan if (2) he is capable of it. Otherwise, the duty to fast is waived for him, and according to most scholars, he must personally feed one needy person for each day; according to Mālik, nothing is required of him. As for the report in the Sunnah concerning a person fasting on behalf of his relative, it applies to vows, as the Companions who narrated it explained and as its wording indicates, for the Prophet said:
“Whoever dies owing a fast, his relative should fast on his behalf.” (3)
A vow remains his liability, and it (4) is incumbent upon him. By contrast, fasting Ramadan is neither an outstanding liability nor incumbent upon him; rather, it is waived for one who is incapable of it.
Since no one can ever perform the five prayers or fast Ramadan on behalf of another, there is no substitute for either, unlike Hajj and other acts. For this reason, the Lawgiver, by way of leniency and mercy, granted a person with an excuse latitude to make them up because he needs to do so. As for other acts, He granted no one latitude to make them up, because there is no need (5) to make them up in view of the substitute that has been prescribed,