This shloka (10.4) and the next (10.5) together form a single long list. Krishna is declaring: whatever arises in the human mind — whether noble or otherwise — all of it comes from Me. Intellect, knowledge, clarity, but also fear, suffering, and absence. Every inner state has a single origin.
What surprises many is that this list does not contain only virtues. Fear is here. Suffering is here. Non-being is here. The meaning runs deep: the divine source is not the origin of only the pleasant. It is the origin of all existence. When a person sees this, life's difficult moments no longer feel like punishments. They are part of the same whole.
This perspective offers a kind of inner steadiness. If both joy and grief come from the same source, then neither can truly overwhelm the person who knows that source.