With accent marks:
Долг платежо́м кра́сен.
The beauty of a debt is its payment
This proverb reminds us that we should always pay our debts back.
The word красен here comes from красный (red). In the old times, красный meant красивый.
The closest English equivalent is "One good turn deserves another".
Other Russian proverbs
Some to the forest, some for firewood.
A bad example is contagious.
Water wears away a stone.
Make a fool pray to God - he will break his forehead.
The quieter you go, the further you'll get.
Put your trust in God, but don't make mistakes yourself
One head is good, but two ones are better.
A bird is visible by its flight.