Duppañña sutta: Witless

Then a mendicant went up to the Buddha … and asked him, “Sir, they speak of ‘a witless idiot’. How is a witless idiot defined?”

“Mendicant, they’re called a witless idiot because they haven’t developed and cultivated the seven awakening factors. What seven? The awakening factors of mindfulness, investigation of principles, energy, rapture, tranquility, immersion, and equanimity. They’re called a witless idiot because they haven’t developed and cultivated these seven awakening factors.”