Twelve Children within Seven Years

When Jacob visited with his uncle Laban, he agreed with Laban to work for him seven years in order to marry his cousin Rachel. He served seven years for her, and when his time was completed, he was given Rachel's sister Leah to marry. When he protested, after a week Laban also gave him Rachel as a wife if he would agree to work for him another seven years (Gen. 29:20-28). Over the next seven years, his wives gave birth to twelve children (Gen. 29:31-30:24). The usual way to understand the text is that Jacob did not marry either woman until the first seven years were completed. However, a recent writer has argued that he must have married them earlier because seven years is not enough time to have twelve children. The writer's math is simple: nine months times twelve children is one hundred and eight months, which is almost nine years. The problem with this is that the writer seems to be assuming that two wives could not be pregnant at the same time.

In fact, there is plenty of time for Jacob's wives to have borne twelve children in seven years. The time between conception and birth averages 38 weeks, which is nine lunar months. A lunar month is approximately 29.5 days, yielding some months having 29 days and an equal number having 30 days. In seven years' time, there are 86.67 lunar months. The Law of Moses specifies that a woman was in a state of uncleanness for 40 days (about one and a third months) after the birth of a son and 80 days after the birth of a daughter (Lev. 12:1-5). If one assumes that this was a practice during Jacob's time, then a pregnancy could take place every ten and a third months for the same woman. Thus, when Leah had her first four sons (Reuben, Simeon, Levi, and Judah), it is possible that 40 lunar months had elapsed (Gen. 29:31-35). The writer mentioned above seems to assume that Rachel did not become jealous of her sister and offer her maid Bilhah to Jacob as a wife and surrogate mother until after Leah had borne four sons (Gen. 30:1-4). However, Hebrew narratives are often not told in strict chronological order, but events that happened previously are told at the point that they impact the story! It is quite possible that Bilhah gave birth to Dan (Gen. 30:5-6) shortly after Judah was born, perhaps a month, meaning that 41 months had elapsed. What is important here is the birth order of Jacob's sons, which plays a role later on in the narrative (Gen. 43:33). Adding another ten and a third months would give the birth of Naphtali (Gen. 30:7-8) at 51.33 elapsed lunar months. Assuming that Leah earlier realized that she too could use her maid as a surrogate mother and gave Zilpah to Jacob as a wife, Gad could have been born a month later with Asher an additional ten and a third months, giving 62.67 elapsed lunar months (Gen. 30:9-13). It is also possible that Issachar could have been born to Leah (Gen. 30:17-18) shortly after, perhaps a month later at 63.67 elapsed lunar months. It is also possible that Zebulun was born ten and a third months later at 74 elapsed lunar months and Diana likewise at 84.33 elapsed lunar months (Gen. 30:19-21). Finally, Joseph could have been born to Rachel a month later, at 85.33 elapsed lunar months (Gen. 30:22-24). While there is some leeway in these figures, it shows that these twelve births are possible within the 86.67 lunar months that make up seven years. There is no reason to suppose that Jacob had to take his wives before the first seven years were up.