Albert Barnes Commentary Proverbs 10:4

"He becometh poor that worketh with a slack hand; But the hand of the diligent maketh rich." — Proverbs 10:4 (ASV)

Slack - The word is elsewhere translated as “deceitful” (Job 13:7; Psalms 120:2–3; Hosea 7:16; Jeremiah 48:10). The two thoughts run easily into each other.