Three idiotic generations

The members of that family were very idiotic. One day, the grandfather told his grandson to take two coins and two bowls to the market to buy fish sauce and soya sauce. The little boy went off for a long time and then came back and asked his grandfather:- My granddad, which coin is for fish sauce and which coin is for soya sauce?The old man got angry and shouted:- What a nonsense! You can buy fish sauce and soya sauce with either of them.The little boy went off for a long time and then came back again. He showed the two bowls out and asked:- My granddad, but which bowl will contain fish sauce and which bowl will contain soya sauce?The old man flew into a passion and gave his grandson some whips. At the moment, the little boy's father got home. Seeing his father beating his son, he got angry and said:- Ah, you are beating my son! Then I'll beat yours!And then he took the whip and beat himself fiercely.The old man also got angry. He pointed to his son's face and said:- Well, you dare beat my son then what can stop me hanging your father?And then, he looked for a rope to hang himself.