Bhashya
स च मद्गुः प्राणः स्वविषयमेव च दर्शनमुवाच प्राणः कलेत्याद्यायतनवानित्येवं नाम ।आयतनं नाम मनः सर्व-करणोपहृतानां भोगानां तद्यस्मिन्पादे विद्यत इत्यायतनवा-न्नाम पादः ॥
In plain words
That same prana, like a diver bird, declared perception itself to be its proper sphere. Prana is a part, named as possessing a foundation. This foundation is the mind—the gathering place for all experiences brought by the senses. That in which this quarter is found is therefore called the quarter possessing an abode.
Close to the Sanskrit
And that diver bird prana spoke of perception itself as its own object, prana is a part, thus named possessing an abode. Abode by name is the mind, of all enjoyments brought by all senses, that in which foot is found, is named the quarter possessing an abode.