As for the legal reasoning: recitation of al-Fatihah is obligatory only while standing, but standing is waived here out of necessity in order to follow the imam. Since standing is waived for him, the obligatory remembrance required in that position—namely, the recitation of al-Fatihah—is likewise waived.
No Recitation Is Required of the Follower
His statement, “No recitation is required of the follower,” means that the follower is not obligated to recite along with the imam, neither in the silent prayer nor in the audible prayer. Accordingly, if the follower says the takbir with the imam at the beginning of the first rak'ah, then remains silent until the imam bows and follows him; then stands for the second rak'ah and remains silent until the imam bows; and does likewise in the third and fourth rak'ahs, we would say to him: Your prayer is valid, because no recitation is required of the follower—neither al-Fatihah nor anything else.
The evidence is the hadith: “Whoever has an imam, the imam’s recitation counts as his recitation.” (1) This is general and includes both the silent and audible prayers, and it explicitly states that the imam’s recitation is recitation for the follower.
However, this hadith is not authentically established from the Prophet, peace and blessings be upon him. Ibn Kathir, may Allah have mercy on him, said in his Tafsir (2): “It has been narrated from Jabir as a statement of his, and that is more authentic.” Al-Hafiz Ibn Hajar said in al-Fath (3): “It is weak according to the hadith masters.” If it is weak, then it cannot be used as evidence, because the sound use of a hadith as proof depends upon two conditions:
The first condition: that the hadith be authentically established from the Messenger, peace and blessings be upon him.
The second condition: that its indication of the ruling be sound. For if it is not authentically established from