I have recently begun reading Jean Danielou's book The Bible and the Liturgy. In it, he examines the sacraments and the liturgical year through the lens of typology. Here are a few words from his introduction on the symbolism of Baptism.
"We usually interpret the rite of Baptism by seeing in it a reference to water as cleansing and purifying. But now this does not seem actually to be the most important of the rite. Two references in the Bible set us on the track of other interpretations. On the one hand, the water of Baptism is the water that destroys, the water of judgement; or "the waters" in Jewish symbolism are actually a symbol of the power of death. But the water of Baptism is also the water that brings forth a new creature, and this sends us back to the Jewish symbol of the waters as not only destructive but also creative. And, finally, the Jewish baptism may also have referred to the crossing of the Red Sea."
Here are a few words on the symbolism of the Lord's Supper:
"The choice of bread and wine may well have contained a reference to the sacrifice of Melchisedech [Melchizedek]; and the framework of a meal a reference to the sacred meals of Judaism, figures of the messianic feast; the season of the Pasch, a reference to the paschal meal the symbol of the alliance between the People and God. We can thus see how the deeds of Christ are charged with biblical memories which tell us the true significance of these deeds."