The early Christians started the first prayers in repetition. It developed even before Mary left us. In the 13th century, while repeating the Hail Mary prayers, our Lady appeared to St. Dominic and told him to spread her “Psalter” his 150 prayer. The Rosary is, as we know it today.
The custom comes from the pharisees who used to pray in sequence and kept count on their phylacteries they had wrapped around their arm even to this day.
The Apostles Creed wasn’t perfected until about the year 200. The Christians did not wear phylacteries and most likely used their 10 fingers for counting.
Look it up in a Catholic Encyclopedia preferably 1912-13. Also Jewish religious customs.
In Christ Joseph