What was the significance of the blank letter given to Amal by the Headman?

Answer: In the Act -II of the play The Post Office by Rabindranath Tagore, Amal was waiting for King's letter when he was on the bed getting very ill. Then the Headman entered the room and handed over a blank Piece of paper to Amal saying that King had sent the letter. Amal did not understand this mockery and tried to read the letter. But he found nothing on the paper. He thought that it was due to his illness and asked the Headman to read the letter for him. Headman ridiculed Amal saying that King would arrive very soon and King would prefer to eat puffed rice in Amal's house. But within short time the mockery of the Headman became true and the King's herald and physician arrived Amal's house. So, it was clear that there may be a possibility even in a blank paper.