ज्योतिषामपि तज्ज्योतिस्तमसः परमुच्यते।ज्ञानं ज्ञेयं ज्ञानगम्यं हृदि सर्वस्य विष्ठितम्।।13.18।।
jyotiṣhām api taj jyotis tamasaḥ param uchyate jñānaṁ jñeyaṁ jñāna-gamyaṁ hṛidi sarvasya viṣhṭhitam
jyotiṣhām—in all luminarie; api—and; tat—that; jyotiḥ—the source of light; tamasaḥ—the darkness; param—beyond; uchyate—is said (to be); jñānam—knowledge; jñeyam—the object of knowledge; jñāna-gamyam—the goal of knowledge; hṛidi—within the heart; sarvasya—of all living beings; viṣhṭhitam—dwells
That Light of all lights is said to be beyond darkness: knowledge, the knowable, and the goal of knowledge, seated in the hearts of all.
13.18 ज्योतिषाम् of lights? अपि even? तत् That? ज्योतिः Light? तमसः from darkness? परम् beyond? उच्यते is said (to be)? ज्ञानम् knowledge? ज्ञेयम् that which is to be known? ज्ञानगम्यम् attainable by knowledge? हृदि in the heart? सर्वस्य of all? विष्ठितम् seated.Commentary The Supreme Self illumines the intellect? the mind? the sun? moon? stars? fire and lightning. It is selfluminous? The sun does
not shine there? nor do the moon and the stars? nor do these lightnings shine and much less this fire. When It shines? everything shines after It all these shine by Its Light. (Kathopanishad 5.15 also Svetasvataropanishad 6.14)Knowledge Such as humility. (Cf.XIII.7to11)The knowable As described in verses 12 to 7.The goal of knowledge? i.e.? capable of being understood by wisdom.These three are installed
in the heart (Buddhi) of every living being. Though the light of the sun shines in all objects? yet the suns light shines more brilliantly in all bright and clean objects such as a mirror. Even so? though Brahman is present in all objects? the intellect shines with special effulgence received from Brahman. (Cf.X.20XIII.3XVIII.61)