We strengthened his kingdom, and gave him wisdom and sound judgment in speech and decision. Sad 38:20 ⧉
Tafsir:
God also blessed David with a very strong empire. The secret of this strength was his wisdom (hikmah) and his decisiveness (fasl al-khitab) which made him capable of taking right decisions at the right time. These two attributes make a ruler efficient. His innate wisdom ensures that he does not take any action which will bring more harm than good. And his ability to distinguish between right and wrong ensures that his decisions will always be based on justice.