द्वित्वं भात्यक्षिदोषेण चन्द्रे स्वे मायया जगत् ।द्वित्वं मृषा यथा चन्द्रे मृषा द्वैतं तथात्मनि ॥ ४ ॥
In plain words
Something goes wrong with the eye and the moon appears double. Through māyā, the world appears in your own Self. The second moon is false — and duality in the ātman is false in exactly the same way.
Close to the Sanskrit
Doubleness appears in the moon through a defect of the eye; the world appears in one's own Self through māyā. As doubleness in the moon is false, so duality in the Self is false.