In the Sacred Scriptures we find both monogamy and polygyny as accepted and expected form of marriage as long as echad is achieved. However, in reading the Scriptures one is brought to the reality that polygyny is the preferred and the most popular form of marriage of the Patriarchs.
By the time of the Exodus polygyny was universal. How do we know this? We can surmise this by the census of Numbers 3:40-43: “YAHWEH said to Moshe, “Register all the firstborn males of the people of Isra’el a month old and over, and determine how many there are. 41 Then you are to take the L’vi’im for me, YAHWEH, in place of all the firstborn among the people of Isra’el, and the cattle of the L’vi’im in place of the firstborn of the cattle belonging to the people of Isra’el.” 42 Moshe counted, as YAHWEH had ordered him, all the firstborn among the people of Isra’el. 43 The total number of firstborn males registered, a month old and over, of those who were counted, was 22,273.”
According to this count we can conclude there were at least 22,273 families, for a family can only have one firstborn. We do however, must include that there were some families that were barren having no children.
Now, let us read Numbers 1:20-46: “The men twenty years old and over who were subject to military service were recorded by name, family and clan… and the grand total came to 603,550.” We won’t even include the men under 20 nor the daughters of these 22,273 families. Just using males over 20…we divide 603,550 by 22,273 you arrive at the figure, 27.09. So are we to understand that 22,273 Israelite households had approximately 28 sons over 20 not including sons under 20 and daughters?
The Patriarch Jacob required 4 wives to produce 12 sons. So we can assume that the average Israelite family would need at least twice as many wives, 8, to achieve 28 sons. This doesn’t even include daughters or me under 20; if you give each family one daughter that would boost the number of children to each household to 56. Not including the male infanticide imposed by the Pharaoh, it is a mathematical exercise to understand the birthrate of the Israelites in Egyptian slavery where murder is common place. Equally the real ratio of births of boys to girls is closer to 51:49 (ignoring these social factors). This means that there is about 107 boys born for every 100 girls. Monogamists will say, see it’s nearly a one to one ratio between boys and girls. But wait, why was the census taken? “The men twenty years old and over who were subject to military service were recorded…” If we include war and tribal conflict, the number of males were culled extensively. According to “Life In Biblical Israel,” by Philip J. King & Lawrence Stager, the average age of death of a typical King was 46; but the life expectancy of the average Israelite was less than 40. This meant there was about a 7 to 1 ratio of women with no hopes of finding a male if monogamy was enforced as the only means of marriage.
Now, we can understand the prophecy concerning the Time of the End, “In that day seven women will take hold of one man and say, ‘We will eat our own food and provide our own clothes; only let us be called by your name. Take away our disgrace!’” (Isaiah 4:1)
Israelite society was a polygynous society. Polygyny was an integral part of Biblical culture.