इमा दिशः सर्वेषां भूतानां मधु ।आसां दिशां सर्वाणि भूतानि मधु ।यश्चायमासु दिक्षु तेजोमयोऽमृतमयः पुरुषो यश्चायमध्यात्मं श्रौत्रः प्रातिश्रुत्कस्तेजोमयोऽमृतमयः पुरुषोऽयमेव स योऽयमात्मा ।इदममृतमिदं ब्रह्मेदं सर्वम् ॥२,५.६ ॥
In plain words
These quarters are the honey of all beings, and all beings are the honey of these quarters. And the shining, immortal person who is in these quarters, and the shining, immortal person here in the ear and in the echo — he is this Self. This is the immortal, this is Brahman, this is all.
The commentators
Bṛhadāraṇyakopaniṣadbhāṣyam· bhāṣya
तथा दिशो मधु । दिशां यद्यपि श्रोत्रमध्यात्मम्, शब्दप्रतिश्रवणवेलायां तु विशेषतः संनिहितो भवतीति अध्यात्मं प्रातिश्रुत्कः- प्रतिश्रुत्कायां प्रतिश्रवणवेलायां भवः प्रातिश्रुत्कः ॥
In plain words
The same is true of the directions. Their inward counterpart is, in general, the ear — but at the very moment a sound comes echoing back, the ear is more present than at any other time. That is why, within you, it is named the echo: the echo is simply what arises the instant a sound returns.
Close to the Sanskrit
So too, the directions' honey: of the directions, although the ear is, in general, the inward correlate, since at the time of the resounding-back of sound it is especially present, therefore, with reference to the self, it is the echo — that which arises at the moment of the resounding-back is the echo.