Forbidden paths
What does Lehi mean by this? Forbidden by whom? A Jewish rabbi comments:
There is a fantastic word-play here that only makes sense in Hebrew. Lehi says that those who fell away did so into “forbidden” paths. The Hebrew word for 'forbidden' is the word אסור (Asur). Now the word for Assyria is the word אשור (Ashur). What had Lehi’s family fled from a few centuries before? The Assyrian captivity that befell upon the Northern kingdom of Israel.
Strange roads
"Strange roads" is also a...well...strange expression. I learned from the Webster 1828 Dictionary that 'strange' used to mean 'foreign' more often than 'weird' in Joseph Smith's time. But there is an explanation from an ancient Israelite perspective that makes more sense. In Hebrew, strange is 'zar' and is often used in connection with idolatry. You see it all over the Old Testament
Leviticus 10:1
And Nadab and Abihu, the of Aaron, took either of them his censer, and put fire therein, and put incense thereon, and offered fire before the Lord, which he commanded them not.
Psalm 81:9
There shall no strange god be in thee; neither shalt thou worship any strange god.Judges 10:16
And they the strange gods from among them, and served the Lord
Etc...
We also read in Lehi's dream in 1 Nephi 8:33
And great was the multitude that did enter into that strange buildingThe great and spacious building is also strange and could to an ancient Israelite be understood as a house of idolatry. To " the work of their own hands" (Isaiah 2:8) is an act of pride which the building is said to represent.
So the forbidden path is a path that leads to destruction, just like Lehi's forefathers had been destroyed and scattered by the Assyrians. The strange road is the road to idolatry.
It amazes me how much meaning can be found in seemingly simple and somewhat odd expressions in the Book of Mormon.