He who does not recite Fatihat al-Kitab is not credited with having observed the prayer.

The Apostle of Allah (ﷺ) said: If anyone observes prayer in which he does not recite Umm al-Qur'an, It is deficient [he said this three times] and not complete. It was said to Abu Huraira: At times we are behind the Imam. He said: Recite it inwardly, for he had heard the Messenger of Allah (ﷺ) declare that Allah the Exalted had said: I have divided the prayer into two halves between Me and My servant, and My servant will receive what he asks. When the servant says: Praise be to Allah, the Lord of the universe, Allah the Most High says: My servant has praised Me. And when he (the servant) says: The Most Compassionate, the Merciful, Allah the Most High says: My servant has lauded Me. And when he (the servant) says: Master of the Day of judg- ment, He remarks: My servant has glorified Me. and sometimes He would say: My servant entrusted (his affairs) to Me. And when he (the worshipper) says: Thee do we worship and of Thee do we ask help, He (Allah) says: This is between Me and My servant, and My servant will receive what he asks for. Then, when he (the worshipper) says: Guide us to the straight path, the path of those to whom Thou hast been Gracious not of those who have incurred Thy displeasure, nor of those who have gone astray, He (Allah) says: This is for My servant, and My servant will receive what he asks for. Sufyan said: 'Ala b. 'Abd al-Rahman b. Ya'qub narrated it to me when I went to him and he was confined to his home on account of illness, and I asked him about it.

The Messenger of Allah (ﷺ) said: One is not credited with having observed the prayer without the recitation (of al-Fatiha). So said Abu Huraira: (The prayer in which) the Messenger of Allah (ﷺ) recited in a loud voice, we also recited that loudly for you (and the prayer in which) he recited inwardly we also recited inwardly for you (to give you a practical example of the prayer of the Holy Prophet).

The Messenger of Allah (ﷺ) entered the mosque and a person also entered therein and offered prayer, and then came and paid salutation to the Messenger of Allah (ﷺ). The Mes- senger of Allah (ﷺ) returned his salutation and said: Go back and pray, for you have not offered the prayer. He again prayed as he had prayed before, and came to the Messenger of Allah (may peace be upon. him) and saluted him. The Messenger of Allah (ﷺ) returned the salutation and said: Go back and say prayer, for you have not offered the prayer. This (act of repeating the prayer) was done three times. Upon this the person said: By Him Who hast sent you with Truth, whatever better I can do than this, please teach me. He (the Holy Prophet) said: When you get up to pray, recite takbir, and then recite whatever you conveniently can from the Qur'an, then bow down and remain quietly in that position, then raise your- self and stand erect; then prostrate yourself and remain quietly in that attitude; then raise yourself and sit quietly; and do that throughout all your prayers.