Bhashya
अथ ह किल इन्द्रः अप्राप्यैव देवान् दैव्या अक्रौर्यादि-संपदा युक्तत्वात् गुरोर्वचनं पुनः पुनः स्मरन्नेव गच्छन् एत-द्वक्ष्यमाणं भयं स्वात्मग्रहणनिमित्तं ददर्श दृष्टवान् ।उदश-रावदृष्टान्तेन प्रजापतिना यदर्थो न्याय उक्तः, तदेकदेशोमघवतः प्रत्यभात् बुद्धौ, येन च्छायात्मग्रहणे दोषं ददर्श ।कथम् ? यथैव खलु अयमस्मिञ्छरीरे साध्वलंकृते छायात्मापिसाध्वलंकृतो भवति, सुवसने च सुवसनः, परिष्कृते परि-ष्कृतः यथा नखलोमादिदेहावयवापगमे छायात्मापि परि-ष्कृतो भवति नखलोमादिरहितो भवति, एवमेवायं छाया-त्मापि अस्मिञ्छरीरे नखलोमादिभिर्देहावयवत्वस्य तुल्य-त्वात् अन्धे चक्षुषोऽपगमे अन्धो भवति, स्रामे स्रामः ।स्रामः किल एकनेत्रः तस्यान्धत्वेन गतत्वात् ।चक्षुर्नासिकावा यस्य सदा स्रवति स स्रामः ।परिवृक्णः छिन्नहस्तःछिन्नपादो वा ।स्रामे परिवृक्णे वा देहे छायात्मापि तथाभवति ।तथा अस्य देहस्य नाशमनु एष नश्यति ।अतःनाहमत्र अस्मिञ्छायात्मदर्शने देहात्मदर्शने वा भोग्यं फलंपश्यामीति ॥
In plain words
And so it is said: Indra, possessing a pure and gentle nature, turning back before he reached the gods, walked on while continually pondering his teacher's words, and saw the fear concerning the mistaken grasp of the self. A portion of the reasoning Prajāpati had taught using the water-pan flashed in Indra's intellect, revealing the fatal flaw in taking the reflection to be the Self. How so? Just as when the physical body is adorned, the reflection is adorned; when clothed, the reflection is clothed; when groomed, the reflection is groomed. When parts like hair and nails are removed, the reflection changes accordingly. Because the reflection shares the exact bodily nature, when the body is blind, the reflection is blind; when diseased, it is diseased; when maimed, it is maimed. And when the body is destroyed, the reflection perishes right along with it. Therefore, I see no enduring fruit in this vision that mistakes either the shadow or the body for the true Self.
Close to the Sanskrit
And as it is said indeed, Indra, without reaching the gods, endowed with the wealth of noble virtues like non-cruelty, continuously remembering the preceptor's word as he went, saw this impending fear concerning the grasping of his own self. The reasoning that was stated by Prajāpati through the example of the water-pan shone forth in part in Maghavan's intellect, by which he saw the flaw in grasping the shadow as the self. How? Just as indeed when this body is well-adorned, the shadow-self is also well-adorned... [omitting full prose paraphrase in translation for brevity] ... Therefore I do not see any enjoyable fruit in this perception of the shadow-self or the body-self.