'[On the octave of Pentecost (Trinity Sunday, the day around 5,000 people received Baptism), at the first holy Sacrifice of the Mass, after receiving her Son in the Blessed Sacrament, at the hands of St. Peter] She [Blessed Mary] remained in a trance, elevated from the floor; but the holy angels shielded Her somewhat from view according to her own wish, in order that the attention of those present might not be unduly attracted by the divine effects apparent in Her. The disciples continued to distribute holy Communion, first to the disciples and then to the others who had been believers before the Ascension.
But of the five thousand newly baptized only one thousand received Communion on that day; because not all were entirely prepared or furnished with the insight and attention required for receiving the Lord in this great sacrament and mystery of the Altar. With regard to the manner of Communion in that day, the Apostles observed the distinction of giving to the most holy Mother and to the one hundred and twenty, upon whom the Holy Ghost had come, both species, of bread and wine; but the recently baptized partook only of the species of bread. But this difference was not made because the new faithful were less worthy of the one species than of the other; but because the Apostles knew, that in either one of the species they received the same Object in its entirety, namely the sacramental God; and that there was no precept, and likewise no necessity that each one receive both species. They considered, that there would be great danger of irreverence and other very grave inconveniences to permit the multitude to partake of the species of the blood, while this was not to be feared of the Communion of the few, who then partook of them at that time.
I have been made to understand, that, for all those who were not consecrating or celebrating, the practice of communicating only the specie obtained from the very beginning of the Church. Although some, that were not priests, for some time partook of both species; yet, as soon as the Church increased and spread over the whole world, she being guided by the Holy Ghost, very wisely ordained, that laymen and those not celebrating Mass should communicate only in the specie of the sacred body; and that it was to pertain to those who were celebrating these divine mysteries, to partake of both species. Such is the secure practice of the Roman Catholic Church.'
Ven. Mary of Agreda, Mystical City of God, Vol. IV, 113