New Revised Standard Version
Woe to you! For you are like unmarked graves, and people walk over them without realizing it.”

Contemporary English Version
But you are in for trouble! You are like unmarked graves that people walk on without even knowing it.

New American Bible
Woe to you! You are like unseen graves over which people unknowingly walk.”

Douay-Rheims Bible
Woe to you, because you are as sepulchres that appear not: and men that walk over are not aware.

Woe to you, because you are as sepulchres that appear not: and men that walk over are not aware.

for.

Numbers 19:16 If any man in the field touch the corpse of a man that was slain, or that died of himself, or his bone, or his grave, he shall be unclean seven days.

Psalm 5:9 For there is no truth in their mouth: their heart is vain.

Hosea 9:8 The watchman of Ephraim was with my God: the prophet is become a snare of ruin upon all his ways, madness is in the house of his God.

Matthew 23:27,28 Woe to you, scribes and Pharisees, hypocrites; because you are like to whited sepulchres, which outwardly appear to men beautiful but within are full of dead men's bones and of all filthiness. . . .

Acts 23:3 Then Paul said to him: God shall strike thee, thou whited wall. For, sittest thou to judge me according to the law and, contrary to the law, commandest me to be struck?