“Trusting in a treacherous man in time of trouble is like a bad tooth or a foot that slips” (v19). The proverbs say that three types of people can cause trouble in a community. The liar (v18) is destructive, like a weapon of war. The “treacherous” or unreliable individual causes pain to others like an abscessed tooth, and the tactless person (v20) strips a person of comfort on a winter day. In contrast, those who can be counted on to do what they promise are refreshing to our souls (v13).
The proverbs teach us that how we treat others is spiritual. Our words, actions, and attitudes demonstrate the depth of our relationship with the Lord (v11-12).