Verse 3.12.6

तावानस्य महिमा ततो ज्यायांश्च पूरुषः । पादोऽस्य सर्वा भूतानि त्रिपादस्यामृतं दिवीति ॥ ३.१२.६ ॥

tāvānasya mahimā tato jyāyāṃśca pūruṣaḥ | pādo'sya sarvā bhūtāni tripādasyāmṛtaṃ divīti || 3.12.6 ||

6. Its glory is like this. But the glory of the puruṣa [i.e., Brahman, who fills the whole world] is still greater. All creatures constitute one quarter of him. The remaining three quarters are nectar in heaven.

Word-for-word explanation:

Tāvān, like this; asya mahimā, its glory; tataḥ jyāyān ca puruṣaḥ, that [i.e., the glory] of the puruṣa [i.e., Brahman, who fills the whole world] is still greater; pādaḥ asya sarvā [i.e., sarvāṇi] bhūtāni, all things constitute one foot [or, quarter] of him; tripād asya, [the remaining] three feet [or, quarters] of him; amṛtam divi, are like nectar in heaven.

Commentary:

Brahman has been described as the gāyatrī, having four feet (or, quarters) and being sixfold. This is just figurative, however. Brahman is Brahman and there is no way of describing it. In reality, it is without name and form, beyond thought and speech. It is the Absolute.

Brahman can be conceived as both the cause and the effect. As the cause (karaṇa) nothing can be predicated about it; it is nirupādhika, without attributes. As the effect (kārya) it is sopādhika, with attributes. Similarly, the gāyatrī is said here to have four quarters and six parts. These are attributes used to help a disciple understand. As the Pañcadaśi says (verse II.58), ‘Niraṃśe api aṃśam āropya....’ (that is, parts are superimposed on that which has no parts in order to explain what cannot be described).