Gerah
Shekels were still a lot of money, if they were paid for between a week’s and a month’s wages. So God broke them down into 20 gerahs. Babylonians and later Jews used shekels of 24 gerahs, but God was clear it was supposed to be 20 (Leviticus 27:25).
This means each gerah would have weighed 0.728 grams of silver, about 1/4th of a US dime. The word in Hebrew means “to drag away”, so presumably these are small pieces of silver that are “dragged away” from the shekel to make the weight balance out correctly.
The gerah was defined by the number of individual barley grains it would weigh against, at (according to tradition, the Bible is silent on this) 16 grains per gerah. We know the shekel’s weight was 14.55 grams, so if it weighed the same as 320 grains of barley (16 grains * 20 gerah= 320 grains/shekel), it meant the barley grains weighed 0.045 grams each, making them a little smaller than today’s grains at 0.048-0.065 grams.
It is likely that a gerah was another commonly available seed like a chickpea or carob seed, which was fairly standardized and easily available. However authorities disagree on which it was, and I can’t find good information on the weights of seeds available to them, so we’ll set it aside for now.
What does all this detail tell us? If you remove the feasts (~18 days) and the sabbaths (52 days), there are about 25 working days per month in a year. If a man earned 1 maneh (60 shekels) per year, he would earn 5 shekels per month, four gerah per day! Why is that so important?
Because it makes a gerah equal to a finger – both are a fourth part of a day/hand! Thus five days of work @ four gerah per day (remember, five is the number of handbreadths between the fingers and the elbow, or the shoulder and the wrist) is equal to 1 shekel! Five of those equal one month’s earnings, and 60 of them equal one mina!
So rather than an hourly wage, there was a quarter-day wage, worth 1 gerah, 1/20th of a shekel! And now that we know what to ask, that’s exactly what the Bible said all along! (Matthew 20:1-9). Notice the times he went out to hire – early in the morning (dawn), and again at the third, sixth, and ninth hours – each of these corresponding to a quarter of the day, one “finger” of a “hand” of the day’s work!
The word translated “penny” was the Roman silver denarius, which weighed 3.9 grams, or about 5 gerah (the denarius was usually traded at 1/4 of a Tyrian shekel). So Jesus was offering them a better-than-fair deal of 5 gerah per day instead of 4 gerah per day. Yet they still complained, just because they worked longer than others who were paid the same.
Back to our point, this shows that 1 gerah per quarter-day is a good typical wage, and thus 1 finger per quarter of the working day, one hand per full day! This means that the wages a man’s arm can bring him are a little over 1 shekel per week, 5 shekels per month, 60 shekels/1 maneh per year.
If he works for 50 years, he will earn precisely one silver talent with his arm! His arm, which is the definition of a cubit – composed of 7 hands, 7 decades of work – 2 of which are for his parents, and 5 of which are his!
