We have seen that in the Pentateuch the numbers "three", "seven", "forty", "seventy" and "four hundred" do not have a precise meaning, but indicate an indefinite quantity, set within certain limits known roughly to the narrator.
We could presume, when it comes to numbers different than these, that they must be accepted as exact and reliable, but it is immediately evident that this is not always so. The ages of the Patriarchs and of others in the Pentateuch, for example, are clearly unacceptable. One then wonders if these figures are casual, without any informative value. However, a thorough examination reveals that not a single one of them is the fruit of the compiler's imagination or of a mania for exaggeration. Rather, they are due to a great error of interpretation.
It would seem that the compiler or some other writer before or after him did not understand the nature of the figures as they came from the original oral or written source. He must have had a veritable passion for numbers, and also evidently had a mania for calculating the ages of the leading figures based on factors given in the narrative. But unfortunately he made no distinction between exact figures and indefinite ones.
Many of the figures given in the Pentateuch are evidently the work of the compiler himself, rather than those handed down by tradition. In particular he must have calculated the Patriarchs' ages and those of the other leading characters, by adding exactly defined periods of their lives to periods of indeterminate duration (i.e. those indicated by the indefinite figures "seven", "forty" and "seventy", which he assumed to be exact). This resulted in a series of figures quite out of proportion and obviously unreliable.
As an example, let us see how he arrived at the figure of one hundred and forty-seven years for Jacob's age. This is the sum total of the figures "40" + 20 + "70" + 17 = 147. Each of these numbers corresponds to the length of time of a clearly defined period in the Patriarch's life, which can be exactly identified on the basis of the text. The first "forty" years refer to those spent in Palestine until Jacob went to Haran in search of a wife, where he then spent twenty years (Gen. 31,38) in the service of his uncle Laban. The following "seventy" he spent in Palestine and the final seventeen (Gen.s 47,38) in Egypt. The true length of Jacob's life can be calculated with a certain degree of reliability, on the basis of the corresponding figures previously quoted. When Jacob left for Haran he could not have been more than twenty years old and when he returned to Palestine he stayed there for more than twenty, but less than thirty. Therefore when he died he must have been a little over eighty.
The ages of others were calculated in the same way, as noted in the following table:
Total duration Calculated periods
Abraham - 175 = "70" + 5 + 25 + "70" + 5
Sarah - 127 = "40" + "40" + "40" + "7"
Isaac - 180 = "40" + "70" + "70"
Jacob - 147 = "40" + 20 + "70" + 17
Joseph - 110 = 17 + 13 + "40" + "40"
Moses - 120 = 40 + "40" + "40"
In the right-hand column the indefinite figures are shown in quotation marks. Each one of the figures represents a period in the life of the person concerned, limited by two significant events. We will see later on, in a detailed analysis, what these periods correspond to for each person and how these figures provide very important elements for the correct interpretation of their lives.
Obviously there is nothing to prevent us from ascribing different numerical values to the "indefinite" figures. We could then consider that the total figures have been split and actually represent the length of the lives of other persons all of the same name. However, if we then attempt to analyse the narrative from this point of view, the whole thing becomes absurd, even ridiculous, and loses all its value. But there is no reason why mere numbers should be so emphasised to the detriment of the narrative, which is almost completely linear, showing a oneness and a continuity that cannot be split into separate episodes.
What sense would there be in the story of the life of Joseph lived by four persons? Of the four, who would be the parents of Manasseh and Ephraim? How many Jacobs would have existed, four or six? How would we have to distribute the four wives and twelve children among them? The whole biblical story would become an unverifiable and senseless hodgepodge.
On the other hand, on the basis of the proposed theory using indefinite periods of time, the entire narrative becomes perfectly clear, coherent and rational. The length of the Patriarchs' lives is brought within acceptable limits and can be evaluated with a fair approximation. And, all the biblical events assume more "human" proportions of time.