Basic explanation
Ride to find another horse. The original metaphor is to find a more satisfactory job while occupying a position. Now Dobby's metaphor is here, and I'm still looking for it everywhere.
tidy
Qing Li Yuan Bo's "Officialdom in Appearance": "At that time, riding a horse to find a horse; As long as you get a lot of money; Earn 112 deductions; There is one in it. "