Christ our Passover is sacrificed for us: Therefore let us keep the feast. 1 Corinthians 5:7–8
In order to understand this hymn, we must know for whom it was written. It was the custom of the early Church that Baptism should be solemnly administered to many catechumens, that is, persons who had been under instruction and preparation for it, on Easter Eve.
This hymn then refers in the first place to them…The Lamb’s high banquet we await. These newly baptized persons were now for the first time about to receive the Holy Communion, and therefore truly waiting for that high banquet.
In snow white robes[theEt stolis albis candidiof the original], because, at baptism, a white garment was given to the persons baptized, with words like these:Take this white vesture for a token of the innocence which, by God’s grace, in this holy Sacrament of Baptism, is given unto thee and for a sign whereby thou art admonished, so long as thou livest, to give thyself to innocency of living, that after this transitory life thou mayest be partaker of life everlasting.
The chrisom-robes were worn from Easter Eve till Low Sunday (all the week-days of the octave are marked in Albis in the Sacramentary of St. Gregory), for which the ancient name wasDominica in albis depositisas in the Ambrosian Missal, or, shortly,Dominica in Albis,because on this day the newly baptized first appeared without the chrisoms, or white robes, which they had worn every day since their baptism on Easter Eve.
John Mason Neale, Short Commentary on the Hymnal Noted, 1853, part I, pages 26–27
The Lamb’s high banquet we await
In snow white robes of royal state;
And now, the Red Sea’s channel past,
To Christ, our Prince, we sing at last.
Upon the altar of the cross
His body hath redeemed our loss;
And tasting of His roseate blood
Our life is hid with Him in God.
That Paschal eve God’s arm was bared;
The devastating angel spared:
By strength of hand our hosts went free
From Pharaoh’s ruthless tyranny.
Now Christ our Paschal Lamb is slain;
The Lamb of God that knows no stain;
The true oblation offered here,
Our own unleavened bread sincere.
O Thou from whom hell’s monarch flies,
O great, O very sacrifice,
Thy captive people are set free,
And endless life restored in Thee.
For Christ, arising from the dead,
From conquered hell victorious sped;
He thrusts the tyrant down to chains,
And Paradise for man regains.