Anādi means He has no source of emanation. But He is ādi. He is the original source of everything. Therefore it is said, anādir ādiḥ. Anādi means He is without any source. But everyone is on account of His presence. Now, it is simple understanding. There is no difficulty to understand God. Anādir ādiḥ. Everyone has got ādi. Just like I have got my father, father has got his father, his father, his..., ādi. Ādi means the original source. But when you go to Kṛṣṇa, or God, He has no ādi. He is self-sufficient. Try to understand the simple formula of understanding God, that God has no origin, but He is the origin of everything.
Now, the next question would be... According to Vedic information, the original person is Lord Brahmā. When there was creation, the first created being was Lord Brahmā. Then from Brahmā, all other living entities expanded. This is the creation understanding. So one may mistake, "Then Lord Brahmā is, the Supreme Personality of Godhead because He has no..., nobody knew that by whom born Lord Brahmā was born." It may be questioned like that. But Brahmā is not the original source of everything. Although he has created this universe, he is not the original source. Therefore it is explained here that the original person is Vāsudeva, or Kṛṣṇa, and He gave intelligence to Brahmā to create this universe. But if we put this argument that "Brahmā was alone.