“If there be light, then there is darkness; if cold, heat; if height, depth; if solid, fluid; if hard, soft; if rough, smooth; if calm, tempest; if prosperity, adversity; if life, death.”
― Pythagoras

From the Ionians, the Pythagoreans adopted the idea of cosmic opposites, which they—perhaps secondarily—applied to their number speculation. The principal pair of opposites is the limit and the unlimited; the limit (or limiting), represented by the odd (3,5,7,…), is an active force effecting order, harmony, and “cosmos” in the unlimited, represented by the even. All kinds of opposites somehow “fit together” within the cosmos, as they do, microcosmically, in an individual person and in the Pythagorean society. There was also a Pythagorean “table of ten opposites,” to which Aristotle has referred—limit-unlimited, odd-even, one-many, right-left, male-female, rest-motion, straight-curved, light-darkness, good-evil, and square-oblong. The arrangement of this table reflects a dualistic conception, which was apparently not original with the school, however, or accepted by all of its members.

https://www.britannica.com/science/Pythagoreanism/Metaphysics-and-number-theory

the early christians (who descended from pythagoreans on the greek side of the lineage) assigned many statements of the type to jesus, and they're all over the bible.

i can't find any direct quotes right now, but it's also the kind of thing that you would expect zoroaster to have said, specifically about duality.

as an aside, one may wonder if pushing duality may harm him with south indian voters.