1. It is a positive Torah commandment to pray every day, as [Exodus 23:25] states: "You shall serve God, your Lord." Tradition teaches us that this service is prayer, as [Deuteronomy 11:13] states: "And serve Him with all your heart" and our Sages said: Which is the service of the heart? This is prayer.

The number of prayers is not prescribed in the Torah, nor does it prescribe a specific formula for prayer. Also, according to Torah law, there are no fixed times for prayers.

2. Therefore, women and slaves are obligated to pray, since it is not a time-oriented commandment.

Rather, this commandment obligates each person to offer supplication and prayer every day and utter praises of the Holy One, blessed be He; then petition for all his needs with requests and supplications; and finally, give praise and thanks to God for the goodness that He has bestowed upon him; each one according to his own ability.

3. A person who was eloquent would offer many prayers and requests. [Conversely,] a person who was inarticulate would speak as well as he could and whenever he desired.

Similarly, the number of prayers was dependent on each person's ability. Some would pray once daily; others, several times.

Everyone would pray facing the Holy Temple, wherever he might be. This was the ongoing practice from [the time of] Moshe Rabbenu until Ezra.

4. When Israel was exiled in the time of the wicked Nebuchadnezzar, they became interspersed in Persia and Greece and other nations. Children were born to them in these foreign countries and those children's language was confused.

The speech of each and every one was a concoction of many tongues. No one was able to express himself coherently in any one language, but rather in a mixture [of languages], as [Nehemiah 13:24] states: "And their children spoke half in Ashdodit and did not know how to speak the Jewish language. Rather, [they would speak] according to the language of various other peoples."

Consequently, when someone would pray, he would be limited in his ability to request his needs or to praise the Holy One, blessed be He, in Hebrew, unless other languages were mixed in with it. When Ezra and his court saw this, they established eighteen blessings in sequence.

The first three [blessings] are praises of God and the last three are thanksgiving. The intermediate [blessings] contain requests for all those things that serve as general categories for the desires of each and every person and the needs of the whole community.

Thus, the prayers could be set in the mouths of everyone. They could learn them quickly and the prayers of those unable to express themselves would be as complete as the prayers of the most eloquent. It was because of this matter that they established all the blessings and prayers so that they would be ordered in the mouths of all Israel, so that each blessing would be set in the mouth of each person unable to express himself.

5. They also decreed that the number of prayers correspond to the number of sacrifices - i.e., two prayers every day, corresponding to the two daily sacrifices. On any day that an additional sacrifice [was offered], they instituted a third prayer, corresponding to the additional offering.

The prayer that corresponds to the daily morning sacrifice is called the Shacharit Prayer. The prayer that corresponds to the daily sacrifice offered in the afternoon is called the Minchah Prayer and the prayer corresponding to the additional offerings is called the Musaf Prayer.

6. They also instituted a prayer to be recited at night, since the limbs of the daily afternoon offering could be burnt the whole night, as [Leviticus 6:2] states: "The burnt offering [shall remain on the altar hearth all night until morning]." In this vein, [Psalms 55:18] states: "In the evening, morning and afternoon I will speak and cry aloud, and He will hear my voice."

The Evening Prayer is not obligatory, as are the Morning and Minchah Prayers. Nevertheless, the Jewish people, in all the places that they have settled, are accustomed to recite the Evening Prayer and have accepted it upon themselves as an obligatory prayer.

7. Similarly, they instituted a prayer after the Minchah Prayer [to be recited] close to sunset on fast days only, its purpose being to increase supplication and pleading because of the fast.

This is called the Ne'ilah prayer, as if to say that the gates of Heaven are closed behind the sun, which becomes hidden, since it is recited only close to [the time of] sunset.

8. Thus, three prayers are recited daily: the Evening Prayer, the Morning Prayer, and the Minchah Prayer. There are four on Sabbaths, festivals and Rosh Chodesh: the three that are recited daily and the Musaf Prayer. On Yom Kippur, there are five: these four and the Ne'ilah prayer.

9. The number of these prayers may not be diminished, but may be increased. If a person wants to pray all day long, he may.

Any prayer that one adds is considered as a freewill offering. Therefore, one must add a new idea consistent with that blessing in each of the middle blessings. [However], making an addition of a new concept even in only one blessing is sufficient in order to make known that this is a voluntary prayer and not obligatory.

In the first three [blessings] and the last three [blessings], one must never add, detract or change anything at all.

10. The community should not recite a voluntary prayer, since the community does not bring a freewill offering. Even an individual should not recite the Musaf Prayer twice, once as the obligation of the day and the other as a voluntary prayer, because the additional offering is never a freewill offering.

One of the Geonim taught that it is forbidden to recite a voluntary prayer on Sabbaths or holidays, since freewill offerings were not sacrificed on these days, but only the obligatory offerings of the day.