Proverbs 30:15-33

Numerical proverbs.
v.15a The leech has two daughters named Give and Give (or give, give, they cry, ESV text note). The point may be an observation of someone who is demanding of you and never satisfied.
v.15b-16 This proverb uses the formula n, n+1. Three things are never satisfied, four never say enough: (1) Sheol, (2) the barren womb, (3) land never watered, and (4) a fire that is never quenched. Life is full of such situations.
v.17 A curse, this proverb says that a child who does not honor his parents will die (using the metaphor of an eye picked out by ravens).
v.18-20 Three things are too wonderful, four I don't understand: (1) the way of an eagle in the sky, (2) the way of a serpent on a rock, (3) the way of a ship on the high seas, and (4) the way of a man with a virgin. Verse 20 is perhaps a key to the significance of the list of four situations. The eagle, serpent, and ship move along but leave no mark (an likewise the man with the virgin, assuming she stays a virgin). Likewise an adulteress leaves no mark but there are consequences to her behavior.
v.21-23 Under three things the earth trembles, under four it cannot bear: (1) a slave who becomes king, (2) a fool filled with food, (3) an unloved woman when she gets a husband, and (4) a maidservant when she displaces her mistress. Such persons are insufferable (like someone at work promoted beyond his or her level of competence).
v.24-28 Four things on earth are small but very wise: (1) ants are not strong but they provide their food in summer, (2) rock badgers are not mighty but they make their homes in the cliffs, (3) locusts have no king but they march in ranks, (4) the lizard you can hold in your hand but it lives in king's palaces. Each provides an important life lesson (e.g., ants teach us to make provision for the future).
v.29-31 There are three things that walk stately, four that strut about: (1) the lion, (2) the rooster, (3) the he-goat, and (4) a king whose army is with him. The majesty of a king is not in himself (like the animals) but in his subjects.
v.32-33 If you have acted foolishly by exalting yourself or planning evil, put a hand over your mouth and keep silent. For as the churning of milk produces curd, so stirring up anger produces strife.

Read Proverbs 30:15-33