PUZZLEVILLA

One evening, a man who had a business of manufacturing shields and spears came to the empero's palace.
"Jahanpanah, nobody in this world could make spears or shields to equal mine," the man said.
"The shields I make are so powerful that nothing can pierce them, and the spears I manufacture are so sharp that there is nothing they are unable to pierce."
Raja Birbal suddenly said, "I can prove you wrong perhaps in a span of just a second."
"That is not possible at all!" exclaimed the man with a note of victory in his voice.
However, he was proved wrong with Birbal's next statement.
What did Birbal say?