To buy the pig in the bag.
More Swedish Proverbs:
The day we fear hastens toward us, the day we long for creeps.Swedish
The best place to find a helping hand is at the end of your own arm.
Swedish
When the well is dry, we know what it's worth.
Swedish
The dogs in Lund bark.
Swedish
Manure and diligence makes the farmer rich.
Swedish
The afternoon knows what the morning never suspected.
Swedish