The mark in Ezekiel 9
“Go through the midst of the city… and set a mark upon the foreheads of the men that sigh and that cry over all the abominations that are done in the midst thereof.” English Bibles say “a mark.” The Hebrew word is taw, this letter's own name.
In the paleo-Hebrew script of Ezekiel's day, that letter was written ✕. So the mark on the forehead was, as a matter of how the alphabet was drawn at the time, a cross-shape.
Keep the two claims apart. That the letter was shaped that way is a fact about handwriting, checkable against inscriptions in the ground. That the passage is about the cross is a reading — an ancient one with a long history, set out in the readings band and in the full Taw study behind the door below.
““Go throughout the city of Jerusalem,” said the LORD, “and put a mark on the foreheads of the men sighing and groaning over all the abominations committed there.””
Ezekiel 9:4→
“Slaughter the old men, the young men and maidens, the women and children; but do not go near anyone who has the mark. Now begin at My sanctuary.” So they began with the elders who were before the temple.”
Ezekiel 9:6→