Proverbs 27:1 - Joseph Benson’s Commentary on the Old and New Testaments

Boast not thyself of to-morrow Of any good thing which thou purposest to do, or hopest to receive to-morrow or hereafter; for thou knowest not what a day may bring forth What may happen in the space of one day to hinder thy designs or expectations. The day is said to bring forth what God, by his almighty power and providence, either causes or suffers to be brought forth or done in it. “The wise man,” says Melancthon, “here teaches us modesty; and prohibits those two great vices, confidence in ourselves, or any thing we have; and rashly undertaking unnecessary things, out of a foolish hope they will succeed according to our desires. Wise and good men will only meddle within the bounds of their calling; and will also depend on God for his blessing; but they will not attempt things without just cause, presuming they can carry them as they please.”