Abraham weighed out 400 shekels of silver for the field of Machpelah (Genesis 23:16) in the first recorded real estate transaction in Scripture. Job longed for his grief to be weighed (shaqal) against all the sand of the sea (Job 6:2). Most dramatically, the mysterious handwriting at Belshazzar's feast included "TEKEL" — a form of shaqal — meaning "You have been weighed in the balances and found wanting" (Daniel 5:27). God's standard of measurement is perfect (Proverbs 16:11).
Shaqal means to weigh on scales, to measure value, or to pay by weight. From this root comes the word "shekel" (sheqel), the most common unit of weight and currency in the Old Testament. Weighing was the primary means of commercial transaction in Israel before coined money.