'Foreheads' in the Bible

"Do not damage the earth or the sea or the trees until we have put a seal on the foreheads of the servants of our God."

Then I looked, and here was the Lamb standing on Mount Zion, and with him were one hundred and forty-four thousand, who had his name and his Father's name written on their foreheads.

and they will see his face, and his name will be on their foreheads.