Didache

But let not your fasts be with the hypocrites; for they fast on the second and fifth day of the week; but do ye fast on the fourth day and the Preparation (Friday). Neither pray as the hypocrites; but as the Lord commanded in His Gospel, thus pray: Our Father who art in heaven, hallowed be Thy name. Thy kingdom come. Thy will be done, as in heaven, so on earth. Give us to-day our daily (needful) bread, and forgive us our debt as we also forgive our debtors. And bring us not into temptation, but deliver us from the evil one (or, evil); for Thine is the power and the glory for ever. Thrice in the day thus pray.