1. Receive, my children, the Rule of Faith, which is called the Symbol (or Creed). And when ye have received it, write it in your heart, and be daily saying it to yourselves; before ye sleep, before ye go forth, arm you with your Creed. The Creed no man writes so as it may be able to be read: but for rehearsal of it, lest haply forgetfulness obliterate what care hath delivered, let your memory be your record-roll: what ye are about to hear, that are ye to believe; and what ye shall have believed, that are about to give back with your tongue. For the Apostle says, “With the heart man believeth unto righteousness, and with the mouth confession is made unto salvation.” For this is the Creed which ye are to rehearse and to repeat in answer. These words which ye have heard are in the Divine Scriptures scattered up and down: but thence gathered and reduced into one, that the memory of slow persons might not be distressed; that every person may be able to say, able to hold, what he believes. For have ye now merely heard that God is Almighty? But ye begin to have him for your father, when ye have been born by the church as your Mother.
Augustine in De symbolo ad catechumenos (A Sermon to the Catechumens) in Nicene and Post-Nicene Fathers 1.3, Augustin: On the Holy Trinity, Doctrinal Treatises, Moral Treatises (HT: Big Mike).