इदं वै तन्मधु दध्यङ्ङाथर्वणोऽश्वि-भ्यामुवाच ।तदेतदृषिः पश्यन्नवोचत् ।रूपं रूपं प्रतिरूपो बभूव तदस्य रूपंप्रतिचक्षणाय ।इन्द्रो मायाभिः पुरुरूपईयते युक्ता ह्यस्य हरयः शता दशेति ।अयं वै हरयोऽयं वै दश च सहस्राणिबहूनि चानन्तानि च तदेतद्ब्रह्मापूर्वमन-परमनन्तरमबाह्यमयमात्मा ब्रह्म सर्वा-नुभूरित्यनुशासनम् ॥ १९ ॥
In plain words
This is the honeyed teaching Dadhyañc, son of Atharvan, once gave to the twin Aśvins. Seeing it directly, the seer spoke: 'Form after form, he has become its matching counterpart, so that his own form might be seen. Through his powers, Indra appears in countless shapes — his senses stand yoked like steeds, a hundred and ten of them.' These are the steeds; these are the ten, and the thousands beyond them, many and without end. And this — this is brahman: nothing before it, nothing after it, nothing inside it, nothing outside it. This self is brahman, the one who experiences everything. So the teaching stands.
Close to the Sanskrit
This indeed is that madhu which Dadhyañc, descendant of Atharvan, told to the two Aśvins. This the seer, seeing it, declared: 'Form by form he has become the counterpart-form; that is his form, for the sake of its being manifest. Indra, by his powers, is perceived as many-formed; for his steeds are yoked, indeed — a hundred, ten.' This indeed is the steeds; this indeed is ten, and thousands, many and endless. This is that brahman: without a before, without an after, without an interior, without an exterior; this self is brahman, the experiencer of everything. Thus is the teaching.