mama dehe guḍākeśa
yac cānyad draṣṭum icchasi
No one can see the entire universe while sitting in one place. Even the most advanced scientist cannot see what is going on in other parts of the universe. But a devotee like Arjuna can see everything that exists in any part of the universe. Kṛṣṇa gives him the power to see anything he wants to see, past, present and future. Thus by the mercy of Kṛṣṇa, Arjuna is able to see everything.