Ancient Dominican Sequence of Our Lady

 Bl Humbert of Romans, 5^th Master General of the Dominican Order, explained why Our Lady is specially honoured on Saturday, and even cited the Sequence then sung at Mass on Saturdays; hereunder, my translation:

From The Exposition of Master Humbert on the Constitutions of the Friars Preachers.

XXIV. Why the Sabbath is attributed to the Blessed Virgin.

And it is expedient not to be ignorant why those who are devout to the Blessed Virgin honour her more on Saturday than on another day.

[i] Therefore it must be attended to that on the Sabbath day it is said that the Lord rested: also, he rested in her as if in his tabernacle.  Thus the Sabbath and the Virgin accord, for the Saturday is the time, and she is the place, of the rest of the Lord.

[ii] Also, on the Sabbath the work of creation was completed, or, of nature: while in her was completed the work of re-creation, or, of grace.  Bernard [says]: In thee and through thee, Most Benign, the hand of the Creator hath re-created whatsoever it had created; therefore she and the Sabbath accord in this manner of completion.

[iii] Also, the Sabbath day was blessed above the other days, whence Genesis 2 [says]: The Lord blessed the seventh day; also, she is blessed above all women.

[iv] Also, the Sabbath day was holier than the rest, whence also in the same [chapter it says]: And he hallowed it.  And she is holier than everyone.  Wherefore it is fitting that the one blessed above others and holier than all is more specially to be honoured on the blessed day and on the holier day.

[v] Again, as the Sabbath day is mid-way between the Day of Venus [Friday] which is that of suffering, and the Lord’s Day which is the day of joy, and neither is anyone able to pass from that day of suffering to the day of joy, unless through the Sabbath day; so neither from the suffering of this world to the joy of heaven is anyone able to pass, unless by the Mediatrix of the world herself.

[vi] Again, as the Saints say, the others failed [in faith] on the Sabbath day, she stood by her faith.

[vii] Again, the Sabbath day is filled by her doing many miracles, and coming to the aid of men, as the example is given by John Beleth, of a certain icon of her, whose veil was lifted up on the Sabbath day.  And there are many others similar.

These therefore are the seven reasons why it is we serve her more on the Sabbath day, doing devoutly and solemnly her whole Office in the church.

Then even in the office of the church is sung a certain sequence of her proper to the Saturday, in which the preceding reasons are touched on why Saturday is more specially attributed to her:

Jubilemus in hac die

Quam Reginæ cœli piæ

Dicavit Ecclesia.

Hæc est dies in qua sua

Vota tibi, Virgo, tua

Reddit hæc familia.

Omne sæculum, omni die

Servi Virgini Mariæ:

Sed in hac devotius.

In hac psallas, in hac ores,

In hac laudes et labores,

Et cantes jucundius.

Virgo quæ non habet parem

Diem sibi singularem

Non injuste vindicat.

O quam digne sibi dari

Diem hunc et consecrari

Res inspecta prædicat!

Hodiernæ lux diei

Dies fuit requiei

Plasmatoris omnium.

Sic quievit in Maria,

Dum ipsius in hac via

Virgo fit hospitium.

Cunctæ tunc sunt creaturæ

Factæ dum opus naturæ

Complet Deus hodie.

Universa tunc refecit,

Dum in Matre qui nos fecit

Complet opus gratiæ.

Dies olim benedicta,

Dies quoque sancta dicta

Fuit ista septima.

Quam benedicta dicaris

Scimus, Virgo singularis,

Et quam sis sanctissima.

Dum transis ad gaudiosum

Diem, relinquens pœnosum,

Dies est hæc media.

Hæc de pœnis nos educit

Mediatrix, et adducit

Ad superna gaudia.

In hac die dum desperat

Grex pusillus qui tunc erat

Fidem tenet firmius.

In hac die suspirantes

Ad se, seque deprecantes

Obaudit frequentius.

Veneremur ergo, fratres,

Ut sanxerunt sancti patres,

In hac die Virginem.

Exorantes ut conducat

Nos hic, et tandem perducat

Ad illam dulcedinem.  Amen.

******

Let us rejoice on this day

Which to the pious Queen of heaven

The Church hath dedicated.

This is the day on which their

Vows to thee, Virgin, this

Thy family pays.

Every age, every day

The Virgin Mary is served:

But on this more devoutly.

On this thou sing’st, on this thou pray’st,

On this thou praisest and labourest,

And chantest more happily.

The Virgin who has no peer

To this singular day she herself

Not unjustly lays claim.

O how worthy to be given to herself

This day and to be consecrated

The thing viewed preaches!

The light of today’s day

Was the day of rest

Of the Maker of all.

So he rested in Mary,

When in this way of he himself

The Virgin was made the host.

Then all creatures were

Made when the work of nature

God finished today.

Then all things were re-made,

When in the Mother he who made us

Completed the work of grace.

The day once blessed

And the day called holy

Was the seventh one.

How blessed thou art called

We know, singular Virgin,

And how thou art most holy.

When thou passest to the day

Of joy, relinquishing suffering,

This day is in the middle.

This from pain us led

The Mediatrix, and brought us

To supernal joys.

On this day when despaired

The little flock, she was then

Holding more firmly to faith.

On this day those sighing

To her, and praying to her

She hears more frequently.

Let us revere, brethren,

As hallowed the holy fathers,

On this day the Virgin.

Praying that she conduct

Us here, and at length lead us

To her delight.  Amen.

— Expositio Magistri Humberti super Constitutiones Fratrum Prædicatorum, XXIV. (Quare sabbatum attribuitur Beatæ Virgini). Opera de Vita Regulari, ed. J. J. Berthier O.P., Rome: A. Befani, 1889, Vol. II.