Position of the fingers while making the sign of the cross in the Byzantine fashion
The sign of the cross (Latin: signum crucis), or blessing oneself or crossing oneself, is a ritual blessing made by members of most branches of Christianity. This blessing is made by the tracing of an upright cross or + across the body with the right hand, often accompanied by spoken or mental recitation of the trinitarian formula: "In the name of the Father, and of the Son, and of the Holy Spirit. Amen."
Many individuals use the expression "cross my heart and hope to die" as an oath, making the sign of the cross, in order to show "truthfulness and sincerity", sworn before God, in both personal and legal situations.
The sign of the cross was originally made in some parts of the Christian world with the right-hand thumb across the forehead only. In other parts of the early Christian world it was done with the whole hand or with two fingers. Around the year 200 in Carthage (modern Tunisia, Africa), Tertullian wrote: "We Christians wear out our foreheads with the sign of the cross". Vestiges of this early variant of the practice remain: in the Roman Rite of the Mass in the Catholic Church, the faithful make this gesture on the forehead, on the lips, and on the heart at the proclamation of the Gospel; on Ash Wednesday a cross is traced in ashes on the forehead; holy oil (called chrism) is applied on the forehead for the sacrament of Confirmation (called the Holy Mystery of Chrismation in the Eastern Orthodox Church, as Orthodox call the Sacraments by the name "Holy Mystery"). By the 4th century, the sign of the cross involved other parts of the body beyond the forehead.