Sturdy as an oak.
More Traditional Proverbs:
Only after the last tree has been cut down, Only after the last river has been poisoned, Only after the last fish has been caught, Only then will you find that money cannot be eaten.Traditional
The jug will hold water until it breaks
Traditional
If an ass goes travelling it will not come home a horse.
Traditional
The less people think the more they talk.
Traditional
The greater the man, the greater the crime
Traditional
A kings chaff is worth more than other mens corn.
Traditional