仁王護國般若波羅蜜多經疏 2.271

2.271

解曰：居土漸廣，作天帝釋，廣初地百為千明門，修戒度圓，以十善化。從此第三明發光地，文五如前。

The commentary states: The land they inhabit becomes gradually broader; becoming Śakra, king of the gods, they expand the hundred of the first bhūmi into one thousand gates of illumination, their cultivation of the pāramitā of morality is perfected, and they transform beings through the ten goods. From here, the third section clarifies the Prabhākarī-bhūmi, with its five textual parts as before.