and, when leading his companions in prayer, he would conclude his recitation with ‘Say: He is Allah, One.’ When they returned, they mentioned this to the Messenger of Allah, may Allah bless him and grant him peace. He said, ‘Ask him why he does that.’ They asked him, and he replied, ‘Because it describes the Most Merciful, and I love to recite it.’ The Messenger of Allah, may Allah bless him and grant him peace, said, ‘Tell him that Allah loves him.’”
Al-Bukhārī also stated in the chapter “Combining Two Surahs in One Unit of Prayer”:
‘Ubayd Allāh reported from Thābit, from Anas:
“A man from the Ansār used to lead them in prayer in the mosque of Qubā’. Whenever he was about to recite a surah for them in prayer, he would first recite ‘Say: He is Allah, One’ in full, then recite another surah along with it. He did this in every unit of prayer. His companions spoke to him, saying, ‘You begin with this surah, but then you do not consider it sufficient without reciting another. Either recite it alone, or leave it and recite another.’
“He replied, ‘I will not give it up. If you would like me to lead you in prayer in this way, I will do so; but if you dislike it, I will stop leading you.’ They considered him one of the best among them and were reluctant to have anyone else lead them.
“When the Prophet, may Allah bless him and grant him peace, came to them, they told him what had happened. He said, ‘So-and-so, what prevents you from doing what your companions ask of you, and what makes you adhere to this surah in every unit of prayer?’
“He replied, ‘I love it.’ He said, ‘Your love for it has admitted you to Paradise.’”
The Prophet’s statement, may Allah bless him and grant him peace, “It is equivalent to one-third of the Quran,” is true, just as he said. For he, may Allah bless him and grant him peace, is the truthful one whose truthfulness is confirmed, who does not speak from his own desire. Nothing but the truth ever passed his lips.