The lesser sign of the cross is made before the reading of the Gospel at Eucharist with the thumb of the right hand on the forehead, on the lips and on the breast, just over the heart.
[2] According to the German theologian Klemens Richter [de] the crossing of the congregation when the Gospel is announced is "one of the oldest folk customs attached to the Eucharistic celebration".
"[4] Fellow Catholic theologian Valentin Thalhofer shares this view and references Sicard of Cremona (1155–1215) and Durandus of Saint-Pourçain (1275–1332/1334) as further evidence for the firm establishment of this practise in the 12th century.
[4] A more modern interpretation referenced is that given by Josef Andreas Jungmann (1889–1975), a Jesuit liturgist: Having in mind Romans 1:16 ("For I am not ashamed of the gospel"), the small sign of the cross is seen as a courageous confession of faith.
[7] The Anglican theologian Claude Beaufort Moss (1888–1964) sees the lesser sign as an "ancient practice, signifying that we belong to Christ".
Then he says, A reading from the holy Gospel, making the Sign of the Cross with his thumb on the book and on his forehead, mouth, and breast, which everyone else does as well.