Srila Prabhupada

Prabhupāda: Śaṁbhu is another name of Lord Śiva, Śaṁbhu. Svayaṁbhur nāradaḥ śaṁbhuḥ (SB 6.3.20). He is called Svayaṁbhuḥ, and Śiva is called Śaṁbhu. Vaiṣṇavānām yathā śaṁbhuḥ. Svayaṁbhur nāradaḥ śaṁbhuḥ kumārāḥ kapilo manuḥ. Kumārāḥ. There is a sampradāya from Kumāra, four Kumāras, brahmacārīs. They were sons of Brahmā. When they were born, Lord Brahmā said that, "You now make . . . marry and produce. We want population."
In the creation, in the beginning. So they refused. "Oh, we are not going to marry. We shall remain brahmacārī, devotee." Then Lord Brahmā was angry, "Oh, you are refusing your father's order?" So from when he was angry, his eyes became red. From that, Śiva was born. Therefore his name is Rudra. Rudra. Rudra means anger. So when Lord Śiva becomes angry, the whole thing is finished.
(690514 - Conversation with Allen Ginsberg - Columbus)

Suppose we are worshiping here. The Māyāvādī will say: "They are worshiping a brass, metal Deity." So are we so fools that we are spending so much money for worshiping a lump of metal? That they do not know. This is acintya-bhedābheda. And fact is there. Kṛṣṇa is omnipotent. He can accept your service in any way, as He likes. This is called arcā-vigraha. As Kṛṣṇa's avatāra is there, here is also another avatāra, arcā-vigraha. He is so kind. You cannot see Kṛṣṇa, you cannot touch Kṛṣṇa at the present moment, but Kṛṣṇa is so kind that He appears before you as you can touch, you can dress, you can offer your respect, you can see. That is Kṛṣṇa's mercies. But don't think that Kṛṣṇa has become metal. No. And even if He becomes metal, there is no difference. And what is this metal? That is Kṛṣṇa's energy. We have to understand in that way. So this acintya-bhedābheda-tattva.
(740307 - Lecture CC Adi 07.05 - Mayapur)