Proverbs 26:1-12

The Book of Fools.
v.1 Snow in summer. Honor is not associated with (or not to be given to) fools any more than rain at harvest time (1 Sm 12:17) or snow in the middle of summer. See also v.8. The fool is the stupid person who is worthless and vain (ebc).
v.2 Undeserved curse. Like a flitting sparrow or a flying swallow (i.e., birds never at rest), an undeserved curse will not land on it's intended victim (nlt). Blessing and cursing can have a real effect, but an undeserved curse does not.
v.3 A rod for the back. In this third simile in a row, we are told that as a whip is for a horse and a bridle for a donkey, so a rod is for the back of a fool. A fool is like an animal that can only be guided by force.
v.4-5 How to answer a fool. These two verses appear to contradict each other. v.4 says to not answer a fool according to his folly or you will become like him. v.5 says to answer a fool according to his folly or he may become wise in his own eyes. This illustrates that some proverbs are context sensitive, how you answer a fool depends on the situation. Thus v.4 and v.5 do not contradict each other, some issues are complicated and a single rule can't cover all of the terrain.
v.6 Fool’s message. Do not trust a fool to carry an important message. Doing so is like cutting off your feet (a messenger is like another pair of feet) or drinking violence (i.e., you will suffer harm). See also the lazy messenger at 10:26. You are better off not sending a message at all than sending it by a fool.
v.7 Fool’s proverb. A proverb in the mouth of a fool is like lame legs that hang uselessly. He does not understand it, cannot explain it or use it correctly, and has not implemented it in his life (even though he may repeat it).
v.8 Stupid stone. Like a man who binds a stone in the sling is one who give honor to a fool. The stone is suppose to be slung out of the sling and binding it in indicates that he doesn't know what he is doing and will suffer harm. Likewise giving honor to a fool will cause damage to your reputation when it becomes apparent to everyone that the fool was not worthy of the honor.
v.9 Foolish thorn. A proverb in the mouth of a fool is like a thorn in the hand of a drunkard (23:35). The fool apparently doesn't realize it applies to him. Like in v.7, he doesn't understand it or know how to use it.
v.10 Random archer. Like an archer that shoots at random, causing great harm, is an employer who hires a fool or a drunkard.
v.11 Vomit. Like a dog returning to his vomit is a fool repeating his folly. Though it may cause terrible consequences, yet he repeats it. See 2 Pt 2:21-22.
v.12 Wise in his eyes. There is more hope for a fool than for a man who is wise in his own eyes. A fool might recognize his folly and seek help, but the one who is wise in his own eyes will remain ignorant of his folly.

Read Proverbs 26:1-12