Is it necessary to recite full surah in salah?
All perfect praise be to Allah, The Lord of the Worlds. I testify that there is none worthy of worship except Allah, and that Muhammad is His slave and Messenger.
It is not necessary for a person who offers prayer to recite an entire Surah after Surah Al-Fatihah. While it is preferable to do so, to fulfill what is basically recommended one is only required to recite any portion of the Quran, even if it is just a single verse.
An-Nawawi mentioned in Al-Majmoo': “Fulfilling what is basically recommended is achieved by reciting any portion of the Quran, though a complete Surah is more preferable.”
Similarly, Ibn al-Qayyim stated in Zad al-Ma‘ad: “The Prophet, sallallaahu 'alayhi wa sallam, would usually recite a complete Surah, and at times he would divide the same Surah between two Rak‘ahs (units of prayer).”
Allah knows best.
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