Daodejing Chapter 79: a bitter dispute

When a bitter dispute is settled,
Some bitterness is sure to linger.
How can this be resolved?
The sage holds the left tally,
But never makes a claim on the debtor.
Those who have inner power hold the tally.
Those who lack inner power call in their debts.
The way of heaven has no favourites.
But it stays consistently on the side of the good.

「和大怨，必有餘怨，安可以為善；是以聖人執左契而不責於人。有德司契，無德司徹，天道無親，常與善人。」

Best not lend money to a friend. Even if the debt is repaid, the strain that such a request puts on the relationship can leave a sour taste in both your mouths.

If you do go ahead with a loan, avoid pressing your friend for repayment. The greater the demands you make for the return of the money, the greater the chance of your friendship being destroyed forever. Even if you never see a single dime, you can at least be content that you were able to help your friend through a difficult time when they had nobody else to turn to.

Notes
A loan contract in ancient China was written on a bamboo slip, which was split down the middle into two halves or tallies. The left tally was kept by the creditor and the right tally was retained by the debtor.

Laozi is not advising you to forgive the debt in this passage. He is advocating that you keep the debt open but refrain from pressing for repayment in order to maintain the relationship.