John Gills Exposition of the Bible Commentary - Proverbs 17:18
A man void of understanding striketh hands ,.... With his friend's creditor, and becomes surety for him; and thereby acts a very unwise part, and shows himself to want understanding, by taking such a step, which may prove the ruin of himself and family: for though a man may and should love his friend at all times; yet he is not obliged, under a notion of friendship, to injure himself and his family, or to run the risk of it; if he does, it is a plain case he wants wisdom and discretion, see ... read more
Matthew Henry's Complete Commentary - Proverbs 17:18
Though Solomon had commended friendship in adversity (Prov. 17:17), yet let not any, under pretence of being generous to their friends, be unjust to their families and wrong them; one part of our duty must be made to consist with another. Note, 1. It is a piece of wisdom to keep out of debt as much as may be, especially to dread suretiship. There may be a just occasion for a man to pass his word for his friend in his absence, till he come to engage himself; but to be surety in the presence of... read more