The prime minister dared Rahul to speak in any language — including his mother's. The reference was to Rahul's mother Sonia, who was born an Italian citizen.
Which is what brought about the riposte from Siddaramaiah, with the aid-of-notes punchline thrown in.
Modi's own dare to Rahul had come from an earlier challenge to Modi by the Congress President.
Rahul had recently said that if he spoke in Parliament for 15 minutes, on a range of issues including corruption under the Modi regime, the prime minister would not be able to sit through it.
"The Congress President challenged me saying that if he speaks for 15 minutes in Parliament, I will not be able to sit through it. Him talking for 15 minutes is a big thing and I wonder what a sight it would be," news reports quoted Modi as saying Tuesday at an election rally in Karnataka.
"It is true we will not be able to sit when he talks. That is because he is naamdaar (dynast) and we are kaamdaar (worker). What right do we workers have to sit in front of you? We cannot ever wear good clothes. These things do not hurt us because we have been subjugated for years," Modi added.