Madhusudana: How is the lotus a weapon? They're all weapons. All the symbols in Viṣṇu's hand, are, all the symbols in Viṣṇu's hand are weapons. How is the lotus a weapon?
Prabhupāda: Lotus is blessing. And that disc and club is for punishing. Viṣṇu has to see two ways because He's the Lord. So, as it is said in the Bhagavad-gītā, paritrāṇāya sādhūnāṁ vināśāya ca duṣkṛtām (BG 4.8). Just like the state. State is meant for punishing the criminals and giving protection to the law-abiding citizen. Wherefrom this idea is taken? It is taken from Viṣṇu. Everything. Because He is the supreme maintainer. So everything is required for maintaining. So this gada, the club, and the disc is for punishing the disobedient, the demons, or those who are harassing devotees. To punish them the Viṣṇu-cakra is there.