And to Sarah he said, Behold, I have given a thousand sileen of silver to thy brother; behold, they are to thee a veil of the eyes, inasmuch as thou wast hidden from thine husband one night, and I would have seen thee: for were I to give all that I have it would not suffice (or be proportionate). And the words were debated. And Abraham knew that Abimelek had not come near Sarah his wife.
The Thousand Shekels Abimelech Paid as Sarah's Veil
Targum Pseudo-Jonathan on Genesis 20:16