"Let him that is without stone among you cast the first thing he can lay his hands on"

This quote by Robert Frost is a metaphor for judgement and criticism. It suggests that before someone passes judgement on another, they need to initially examine themselves and their own actions. The phrase "without stone" is a reference to the biblical passage in which Jesus tells his fans to "let him who is without sin cast the first stone". Simply put, Frost is stating that prior to one person criticizes another, they ought to initially take a look at their own actions and make sure they are innocent of the very same thing. This quote is a tip to believe before we speak and to be mindful of our own actions before we evaluate others. It is a pointer to be modest and to recognize that we are all imperfect which we should not be too quick to judge.