Well, sure it has to do with the Sacrifice of the Mass, since it is a part of the Eucharistic Liturgy, coming just before the Preface and the Eucharistic Prayer.
The priest offers the bread and wine which will become the body and blood of the Lord.
Then, after the consecration, again in the First Eucharistic Prayer (it’s a shame this isn’t used more often), we hear the following:
Almighty God, we pray that your angel may take this sacrifice to your altar in heaven.
Then, as we receive from *this altar *the sacred body and blood of your Son, Let us be filled with every grace and blessing.I italicize the references to the heavenly altar and the earthly altar, our sacrifice mirroring and being identified with the eternal offering.