Solomon
Proverbs 10:4ESV·traditional attribution

A slack hand causes poverty, but the hand of the diligent makes rich.

Matthew Henry Presbyterian @wholebiblehenry

We are here told, 1. Who those are who, though rich, are in a fair way to become poor - those who deal with a slack hand, who are careless and remiss in their business, and never mind which end goes foremost, nor ever set their hands vigorously to their work or stick to it; those who deal with a deceitful hand (so it may...

John Gill Reformed Baptist @doctorgill

He becometh poor that dealeth with a slack hand,.... That is either remiss in giving to the necessities of others, according to his abilities, and as cases require; or that is negligent and slothful in his business. Or, "that worketh with a deceitful hand"; or, "with a hand of deceit" (u), as it may be rendered; who pretends to work, but does not; makes a...

Jamieson-Fausset-Brown Reformed @jfbcommentary

slack--literally, "deceitful," failing of its purpose (compare Hos 7:16). maketh rich--(compare Pro 10:22).