Bhagavad Gita Chapter 7, Verse 10

बीजं मां सर्वभूतानां विद्धि पार्थ सनातनम् | बुद्धिर्बुद्धिमतामस्मि तेजस्तेजस्विनामहम् ||

bījaṁ māṁ sarva-bhūtānāṁ viddhi pārtha sanātanam buddhir buddhimatām asmi tejas tejasvinām aham

O Partha, know Me to be the eternal seed of all beings. I am the intelligence of the intelligent, and the brilliance of the brilliant.

Krishna reveals His fundamental nature as the source. 'Bījaṁ māṁ sarva-bhūtānāṁ viddhi pārtha sanātanam'—know Me to be the eternal seed of all beings. Krishna is the original cause, the source from which everything springs. 'Buddhir buddhimatām asmi'—I am the intelligence of the intelligent. 'Tejas tejasvinām aham'—I am the brilliance of the brilliant. This verse shows that Krishna is not just present in intelligence and brilliance—He is their source. All intelligence comes from Krishna. All brilliance comes from Krishna. This connects to verse 7.6's teaching that Krishna is the source of all, and continues the revelation of divine manifestations.