Like lame legs hanging limp is a proverb in the mouth of a fool.
To recommend wisdom to us, and to quicken us to the diligent use of all the means for the getting of wisdom, Solomon here shows that fools are fit for nothing; they are either sottish men, who will never think and design at all, or vicious men, who will never think and design well. 1.
Commenting on Proverbs 26:6-9
The legs of the lame are not equal,.... Or as "the lifting up the legs by one that is lame" (m), to dance to a pipe or violin, is very unseemly, and does but the more expose his infirmity, and can give no pleasure to others, but causes derision and contempt; so is a parable in the mouth of fools; an apophthegm, or sententious expression...
legs . . . equal--or, "take away the legs," or "the legs . . . are weak." In any case the idea is that they are the occasion of an awkwardness, such as the fool shows in using a parable or proverb (see Introduction; Pro 17:7).