Proverbs 17:18
16 What’s the point of a fool having money in hand to buy wisdom when his head is empty? 17 A friend loves at all times, and a relative is born to help in adversity. 18 The one who lacks sense strikes hands in pledge and puts up financial security for his neighbor. 19 The one who loves a quarrel loves transgression; whoever builds his gate high seeks destruction. 20 The one who has a perverse heart does not find good, and the one who is deceitful in speech falls into trouble.
Sirach 29:14
Ben Sira, Ecclesiasticus12 Store up almsgiving in your treasury, and it will rescue you from every disaster; 13 better than a stout shield and a sturdy spear, it will fight for you against the enemy. 14 A good person will be surety for his neighbor, but the one who has lost all sense of shame will fail him. 15 Do not forget the kindness of your guarantor, for he has given his life for you. 16 A sinner wastes the property of his guarantor,
Notes and References
"... In light of the financial danger involved, the silence of the Torah on the matter, and the advice of Proverbs to avoid going surety, one might expect the sage to take a negative view of the practice... However, Ben Sira moves in exactly the opposite direction. He concludes his pericope with an imperative to stand surety for one’s neighbor. This positive command provides a counterpart to the indicative regarding the goodness of the practice in v. 14 and frames the discussion with an inclusio, in which the practice of going surety is urged as an ethical obligation. Granted, it is also tempered with a caution. One should go surety only according to one’s means in order to prevent financial ruin. Yet, in light of the dangerous social situation portrayed in the pericope it is surprising that he advocates the practice at all."
Gregory, Bracley C. "Ben Sira as Negotiator of Authoritative Traditions" in Xeravits, Géza G., et al., editors. Scriptural Authority in Early Judaism and Ancient Christianity (pp. 111-114) De Gruyter, 2013