From Sahih Bukhari (Hadith 7375):
Narrated `Aisha:The Prophet (ﷺ) sent (an army unit) under the command of a man who used to lead his companions in the prayers and would finish his recitation with (the Sura 112): 'Say (O Muhammad): "He is Allah, the One." ' (112.1) When they returned (from the battle), they mentioned that to the Prophet. He said (to them), "Ask him why he does so." They asked him and he said, "I do so because it mentions the qualities of the Beneficent and I love to recite it (in my prayer)." The Prophet; said (to them), "Tell him that Allah loves him
Reference: Bukhari 7375