BG Chap 11 - The form Kṛṣṇa would reveal to Arjuna
Arjuna wanted to see Kṛṣṇa in His universal form, which, although a transcendental form, is just manifested for the cosmic manifestation and is therefore subject to the temporary time of this material nature. As the material nature is manifested and not manifested, similarly this universal form of Kṛṣṇa is manifested and nonmanifested. It is not eternally situated in the spiritual sky like Kṛṣṇa's other forms. The Lord would first show Arjuna the form described in puruṣa-sūkta with a thousand heads, eyes and feet. It is Kṛṣṇa’s expansion, the first puruṣa-avatāra (Mahā-Viṣṇu), whose form is the total of all the devatās, and who is the antaryāmī of prakṛti. Kṛṣṇa asks Arjuna to see His hundreds and thousands of wonderful forms, of various types, of various colors and shapes in one form of His. Then having made Arjuna qualified by that vision, Kṛṣṇa would later show him His form of time.