Srimad Bhagavat Gita commentary chapter 10 verse 21

 Chapter 10 verse 21 

“Amongst the twelve sons of Aditi I am Vishnu; amongst luminous objects I am the sun. Know me to be Marichi amongst the Maruts, and the moon amongst the stars in the night sky.” 

Lord talks about his many vibhuthis-glories with comparisons. He is referring to history of bharata varsha which have been enumerated in Srimad Bhagavatam. I am going to quote again Swami Mukandanandaji’s commentary for this verse as below. 

From the Puranas we learn that Sage Kashyap had two wives— Aditi and Diti. From his first wife, Aditi, he fathered twelve celestial personalities—Dhata, Mitra, Aryama, Shakra, Varuna, Amsha, Bhaga, Vivasvan, Pusha, Savita, Twashta, and Vamana. Amongst these, Vamana was the Avatar of the Supreme Lord Vishnu. Thus, Shree Krishna states that amongst the Adityas (twelve sons of Aditi), Vishnu (in the form of Vamana) reveals his opulence. 

Amongst luminous objects, the sun is supreme. The Ramayan states: 

rākāpati ṣhoṛasa uahiñ tārāgana samudāi, 

sakala girinha dava lāia binu rabi rāti na jāi [v26] 

“At night, all the lamps along with all the stars in the sky and the moon as well are together insufficient in removing the darkness of the night. But the moment the sun rises, the night gets dispelled.” That is the power of the sun, which Shree Krishna reveals as his vibhūti. 

Then, he comes to the night sky. There is the well-known saying, “One moon is better than a thousand stars.” Shree Krishna says that amongst all the constellations and stars in the night sky, he is the moon because it best reveals his opulence. 

The Puranas further relate that Sage Kashyap fathered daityas (demons) from his second wife Diti. However, apart from the daityas, Diti desired to have a son more powerful than Indra (the king of the celestial gods). So she kept her baby in her womb for a year. Indra then used a thunderbolt and split her fetus into many pieces, but it turned into many fetuses. These became the Maruts, or the 49 kinds of winds that flow in the universe, doing tremendous good. The major ones amongst them are Avaha, Pravaha, Nivaha, Purvaha, Udvaha, Samvaha, and Parivaha. The chief wind, known as Parivaha, also bears the name Marichi. Shree Krishna states that his vibhūti (opulence) manifests in the wind called “Marichi.”