an.1.13 Aṅguttara Nikāya (Numbered Discourses)
13
“Mendicants, I do not see a single thing that gives rise to dullness and drowsiness, or, when they have arisen, makes them increase and grow like discontent, sloth, yawning, sleepiness after eating, and mental sluggishness.
When you have a sluggish mind, dullness and drowsiness arise, and once arisen they increase and grow.”
“Mendicants, I do not see a single thing that gives rise to dullness and drowsiness, or, when they have arisen, makes them increase and grow like discontent, sloth, yawning, sleepiness after eating, and mental sluggishness.
When you have a sluggish mind, dullness and drowsiness arise, and once arisen they increase and grow.”