Yawn. You commonly couldnt enter good college without knowing Hebrew and ancient Greek in the 1800s America. Non formal educated, but devout Americans used to commonly be able to read Hebrew, especially pastors from solid ( and not so solid) theological institutes
While it is an ancient language, Hebrew was nearly dead until Israel became a state in 1948. It was more common for educated people here in the US to study Latin and some Greek than Hebrew.
If those writings are chipped in rock, they can be dated rather easily.
They have been documented and dated to the second century AD. The father of modern pictoarcheology was called in to investigate them by our scout troop. After three years he rendered an opinion supporting Irish monks in pre pre-Columbian America.