SB 6.11.19
suresa kasman na hinosi vajram
purah sthite vairini mayy amogham
ma samsayistha na gadeva vajrah
syan nisphalah krpanartheva yacña
Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
O King of the demigods, since I, your enemy, am standing before you, why don’t you hurl your thunderbolt at me? Although your attack upon me with your club was certainly useless, like a request of money from a miser, the thunderbolt you carry will not be useless. You need have no doubts about this.
Purport by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
When King Indra threw his club at Vrtrasura, Vrtrasura caught it in his left hand and retaliated by using it to strike the head of Indra’s elephant. Thus Indra’s attack was a disastrous failure. Indeed, Indra’s elephant was injured and thrown back fourteen yards. Therefore even though Indra stood with the thunderbolt to hurl against Vrtrasura, he was doubtful, thinking that the thunderbolt might also fail. Vrtrasura, however, being a Vaisnava, assured Indra that the thunderbolt would not fail, for Vrtrasura knew that it had been prepared in accordance with the instructions of Lord Visnu. Although Indra had doubts because he could not understand that Lord Visnu’s order never fails, Vrtrasura understood Lord Visnu’s purpose. Vrtrasura was eager to be killed by the thunderbolt manufactured according to Lord Visnu’s instructions because he was sure that he would thus return home, back to Godhead. He was simply waiting for the opportunity of the thunderbolt’s being released. In effect, therefore, Vrtrasura told Indra, “If you want to kill me, since I am your enemy, take this opportunity. Kill me. You will gain victory, and I shall go back to Godhead. Your deed will be equally beneficial for both of us. Do it immediately.”