The works of Ādi Śaṅkarācārya

Bṛhadāraṇyakopaniṣadbhāṣyam

Bhashya

Bhashya

आदर्शे प्रसादस्वभावे चान्यत्र खङ्गादौ, हार्दे च सत्त्व-शुद्धिस्वाभाव्ये च एका देवता; तस्या विशेषणम्- रोचि-ष्णुः दीप्तिस्वभावः; फलं च तदेव, रोचनाधारबाहुल्या-त्फलबाहुल्यम् ॥

In plain words

Whether in a clear mirror or similar surfaces like a polished sword, or within the heart and the natural clarity of a purified mind, the deity is one. Its characteristic attribute is radiant light, and the fruit is that very light itself—the multiplication of results comes simply from the multiplicity of its supports.

Close to the Sanskrit

In a mirror, and in a nature of clarity, elsewhere in a sword etc., and in the heart, and in the inherent nature of mind-purity, there is one deity; its attribute is shining, of luminous nature; and the fruit is that very same one, from the abundance of luminous supports comes the abundance of fruit.