Why keep the dog and bark yourself?

Householders keep dogs to guard their homes by barking when they hear suspicious sounds outside. Figuratively, ‘to keep a dog and bark yourself’ is to do the work that you pay others to do for you.

‘Isn’t it about time you clipped the front hedge, Henry?’ asked his wife.

‘That’s the gardener’s job’ he answered. ‘Why should I keep a dog and bark myself?’