Shulchan Arukh, Orach Chayim 115/שולחן ערוך·אורח חיים קט״ו

1The reason for the blessing of "Ata Chonein" ["You grace humanity with knowledge", the fourth blessing of the weekday Amidah]. Containing 1 S'if:Since humanity's advantage over animals is understanding and intellect, they established the blessing of "Ata Chonein" as the first of the [the Amidah's] middle [blessings] since if we do not have understanding, there is no [capacity for] prayer.