Oresiesis-Heru-sa Ast, on Ezek 9:4

“And the Lord said to him: Go through the midst of the city, through the midst of Jerusalem: and mark Thau upon the foreheads of the men that sigh, and mourn for all the abominations that are committed in the midst thereof.”

“At the beginning of our prayers let us sign ourselves with the seal of baptism. Let us make the sign of the cross on our foreheads, as on the day of our baptism, as it is written in Ezekiel. Let us not first lower our hand to our mouth or to our beard, but let us raise it to our forehead, sing in our heart, "We have signed ourselves with the seal." This is not like the seal of baptism, but the sign of the cross was traced on the forehead of each of us on the day of our baptism.”

Imported from an open dataset — not yet checked against the printed edition.