Here we see the father with two awkward sons - no wonder the poor man looks confused!
Here we are in the vineyard at harvest time. The first son promises to help his father - but then just sits down and does nothing! The second refuses to help - but then changes his mind and helps to pick the grapes.
Obviosuly the second son is far more use to his father than the first - but what a pity they didn't both offer to help and then get on with the job.
How do we treat other people when they ask us to help them?