Bs 5.18

sisṛkṣāyāṁ tato nābhes
tasya padmaṁ viniryayau
tan-nālaṁ hema-nalinaṁ
brahmaṇo lokam adbhutam
Synonyms: 
sisṛkṣāyām — when there was the will to create; tataḥ — then; nābheḥ — from the navel; tasya — of Him; padmam — a lotus; viniryayau — came out; tat-nālam — its stem; hema-nalīnam — like a golden lotus; brahmaṇaḥ — of Brahmā; lokam — the abode; adbhutam — wonderful.
Translation: 
When Viṣṇu lying in the ocean of milk wills to create this universe, a golden lotus springs from His navel-pit. The golden lotus with its stem is the abode of Brahmā representing Brahmaloka or Satyaloka.
Purport: 

"Gold" here means the dim reflection of pure cognition.