Crosses on Head, Lips, and Heart?
The General Instruction of the Roman Missal points out that, just before the Gospel is proclaimed ― as the lector says: “a reading from the Holy Gospel according to…” ― the lector is to “[make] the Sign of the Cross with his thumb on the book and on his forehead, mouth, and breast.” This is, the Instruction explains, what “everyone else does as well” (GIRM 134). Why is that?
Before the deacon heads to the ambo to proclaim the Gospel, he receives a blessing from the priest: “May the Lord be in your heart and on your lips that you may worthily proclaim his Gospel.” Even if there is no deacon, the priest offers this same prayer before proclaiming the Gospel himself.
The congregation’s own little crosses over their heads, hearts, and lips prepare them to receive what’s about to be proclaimed. It tills us into “good soil” for the seed. It is a prayer that we may be, in Jesus’s words, “someone who hears the word and understands it” (Mt 13:23). It is a prayer that we may “love the Lord our God with all our hearts, and with all our souls, and with all our minds” (Mt 22:37) ― a prayer that, as Jesus put it, “by our words we will be justified” (Mt 12:37).