My fellow Jew (let's call him Bob) and I were discussing the Miswa of "You shall not place a stumbling block in front of a blind person (Wayikra 19)". Bob was saying that that verse was referring to the literal translation of the Miswa, meaning that it is Asur to place a stumbling block before a blind man because of this Pasuk. I responded that it means what Rashi quotes from the Mefarshim before him and it has nothing to do with literally placing a stumbling block before a blind person. Then Bob tells me to look at Onkelus which translates the Pasuk into Aramaic literally. I responded that that's not a proof.

Summary:1) Does the Isur of "Lifne Iwer" also mean that you can't place a stumbling block before a blind person (I'm not asking if you're allowed to place a stumbling block, rather I'm asking if you did were you in violation of this Isur)? 2)If I'm right then is there is any source for not placing a stumbling block in front of a blind man?