The word Proskomedia actually means a gift or an offering, but here it does not yet mean the complete offering of gifts as a sacrifice to God, but only their preliminary preparation for this offering.
In ancient times, all believers, not excluding the Kings, going to listen to the liturgy, usually brought bread and wine with them as an offering, as types designated for the sacred rites, but just as for the performance of the Holy Mysteries, only bread was required, and many were brought, then, after choosing the best of them, for taking out the so-called Lamb, the rest were then, just like wine, used for a brotherly loving meal established after the liturgy, during which nobles and rich men of both sexes were not ashamed to serve the poor brethren. - This was done on the basis that the bread and wine used in Proskomedia, as material for the preparation of the Holy Mysteries, remained until the time when they were to be transformed into the body and blood of Christ - only bread and wine, i.e., images of an offering or gift to God.
The actions of Proskomedia depict both the Nativity of Christ (the star, the adoration of the Magi, etc.) and His subsequent suffering; which is why those read during her Prophecy, foreshadowing, etc. relate to these events.
In order to begin Proskomedia, the priest first prepares himself as follows: he prays in front of the Royal Doors; applied to the images of the Savior and the Mother of God; bows his head before the Lord, asking for grace to be sent down to him from above to perform the Great Sacrament; asks those present for forgiveness of his sins and their prayers for him, and upon entering the altar, he prostrates himself three times before the Holy Table (throne), kisses the Gospel, which depicts Christ Himself and the Table as the throne of His dominion. Then he puts on sacred clothes, meaning that when he begins to perform the Sacrament, he apparently separates himself from other people, as a servant of God, and completely devotes himself to the service of God. At the end, he washes his hands as a sign of spiritual washing, cleansing him from all worldly filth, and then proceeds to the altar, pronouncing the troparion of Good Friday, as a confession of the true sufferings of Christ and their blessed fruits in the work of redemption.
Taking one of the five prosphoras, and making a copy of the sign of the cross on it with the threefold pronunciation of the words: in remembrance of the Lord God and our Savior Jesus Christ, he circumcises it on all four sides, saying with each copy the prophetic sayings: Like a sheep led to the slaughter, etc., and taking out the middle, soft part of the prosphora, which has a cross on top (which actually constitutes the Lamb, he puts it on the Paten and cuts it crosswise, piercing the right side of the Lamb with a spear. At the same time, he pours wine dissolved with water into the cup.
All these actions simultaneously depict both the Nativity and the Death of the Savior, since His Nativity was already a preparation for death for the sins of the world. By the same token, the altar itself, on which gifts are prepared during Proskomedia, has different meanings: in relation to Christmas, it marks a nativity scene; Regarding death, it depicts Golgotha.
Having prepared the Lamb, the priest takes the second prosphora and takes out a part from it in honor and memory of the Most Blessed Virgin Mary, asking Her that through Her prayers the Lord will accept this sacrifice and places this part on the paten on the right side of the Lamb. 9 parts are taken out of the third prosphora, in honor of: the Forerunners, Prophets, Apostles, Saints, Martyrs and Martyrs, Holy Unmercenaries and all Saints, as well as in honor of St. John Chrysostom, or Basil the Great, depending on whose liturgy is being celebrated. From the fourth prosphora a portion is taken for the welfare of: the Synod and the spiritual Hierarchy, the Sovereign and the Reigning House and all Orthodox Christians. And finally - from the fifth - for the repose of all those who have died in the faith. Through this, the Lamb, reclining on the paten in the middle of all the taken out parts, appears, as it were, surrounded by the entire army of heaven and earth.
After this, the priest, having taken the star and perfumed it over the censer, places it on the paten on top of the gifts, thereby depicting a star standing over the nativity scene, and then covers both the paten with the star and the chalice with special covers (also perfumed) and on top of both of them puts the so-called air. With all this he depicts that the Divine Power of the incarnate Savior, although it was hidden under the garments of flesh before the time of the testimony of Him by a voice from Heaven, nevertheless existed in Him constantly and inalienably.
As a result, the priest, during these coverings, utters the words: The Lord reigned in beauty, clothed with beauty, etc.
Having prepared the gifts in this way, the priest reverently censes them three times, thereby depicting the worship and gifts to the Newborn Savior from the Magi, who brought myrrh and frankincense; as well as those posthumous aromas that were brought to the tomb of the myrrh-bearer.
After all this, the priest says a prayer, which constitutes the main meaning of Proskomedia or the offering of gifts as a sacrifice to God, in which he asks God the Father, who gave the believers the Heavenly Bread - His Son - to eat, to bless these offered gifts and accept them into his Pre-Heavenly Altar.
Then follows the dismissal, that is, the conclusion of this part of the Divine service, during which the deacon burns incense in the altar and throughout the church, signifying that the grace of the Holy Spirit is mysteriously poured out on everyone present with faith and the Lord is ready to accept their prayers, like a censer before Him.
During the celebration of the Proskomedia in the altar, the hours (3rd and 6th) are read on the choir, consisting of some touching psalms prophesied about the Savior and prayers relating to Him, the Most Holy Theotokos and the Saints of that day. Attentive listening to this reading can serve as the best means of preparing for the mood of the soul of each believer for proper attention and reverence during the Mystery of the Divine Liturgy; and, just as the ancient words of the Prophets prepared people’s faith in the coming Redeemer, so they prepare the feelings of those praying for the contemplation of the great Sacrament of bloodless sacrifice! And that this preparation is necessary, we are assured of this by the words of the Pleasant of God, who said: “Before you pray, prepare yourself: and do not be like a man who tempts the Lord” (Sir. 18:23).
This prayer received the name of the hours from the fact that according to the rules of the Holy Apostles (book 8, chapter 34;, it was supposed to pray: in the morning (i.e. at the 1st hour of the day); at the third hour of the day; at the sixth; at the ninth, in the evening and at the crowing of the loop (i.e. during the first roosters), which was performed by the ancient Christians and is observed to this day by the desert dwellers, who, in addition, even in the intermediate time, between these prayers, read the psalms corresponding to them, which is called the interhour. But since the laity, due to their social duties, could not fulfill this in all severity, the Church decided: The first hour should be added to Matins, ending with the dawn of the day; the Third and Sixth hours should be read before the Liturgy, and the ninth - before Vespers.
On the eve of the days of the Nativity of Christ and the Epiphany, these Hours are called Royal, because the solemn pronunciation of the detailed Royal Title is added to their content and many years are proclaimed to the Sovereign and the entire Royal House.