“The two parts which, in a certain sense, go to make up the Mass, namely, the liturgy of the word and the Eucharistic liturgy, are so closely connected with each other that they form but one single act of worship.”
Sacrosanctum Concilium, 56

The division of the Mass into the two parts, the “Liturgy of the Word” and the “Liturgy of the Eucharist”, is recorded as early as the Second Century.  Both parts are essential to the liturgy, and follow a defined order: the Liturgy of the Word always precedes the Liturgy of the Eucharist, toward which it ultimately points as the summit of the liturgical celebration.  Both parts are means by which Christ is made present to His Church: “He is present in His word, since it is He Himself who speaks when the holy scriptures are read in the Church” (Sacrosanctum Concilium, 7), and He is present in the fullest sense in the Eucharistic species.  This relationship is reflected architecturally by the altar and ambo, in their design and arrangement within the church.

“The origins of the ambo trace back to the early Church where it was set apart and reserved for the public proclamation of the scriptures and the subsequent preaching on those readings.  An ambo, then, is more than a lectern or pulpit; it is something of a ‘sanctuary’ for the word of God.  As such, it is not only functional, but also a sign to those who see it that something important happens within it… At the ambo we are spiritually nourished with the revealed word of God, just as at the altar we are nourished par excellence with the Body and Blood of Christ.  For that reason, an ambo should exhibit a clear relationship in design and materials with the altar itself” (Denis McNamara, Catholic Church Architecture and the Spirit of the Liturgy, 220-221).