Marriages are organic entities in themselves, and as a result, exclusive relationships have value in themselves: “the whole is greater than the sum of the parts.” So it is right and proper that a married person can be jealous not only out of ego-driven aggrandizement, but instead out of the desire to build something together with the other person. Special relationships are meant to be protected, and jealousy is one of the elements of that protective wall.
I think this is true of all good relationships – that there is something intrinsically beautiful about connecting with others, and growing in partnership. Something is created new – not just biologically (with the possibility of children) but also spiritually, where a loving marriage creates and sustains an ongoing source of beauty and goodness in its surroundings. (Business works much the same way – high trust capitalism is a huge wealth creator.)
So it is not crazy that we value the relationships that we generate – indeed, why else do we have the fear of dying alone? And when we value relationships, we are protective of them – we do not want to lose those special relationships into which we have poured our heart and soul.
Relationships in marriage and those between man and G-d are mirror images of each other. Jealousy (the word kaneh) for the relationship between man and G-d is mentioned precisely 13 times in the Torah. Which is quite interesting, because the word for jealousy, kaneh, is used to describe a husband’s jealousy of his wife (the sotah ceremony) precisely 13 times as well! Adultery and idolatry lead to the green-eyed monster in both husband and G-d.
In the Torah, the number 13 is not unlucky – it is all about special relationships, love and unity. The numerical value of the Hebrew letters for “love” ahavah, is also 13.
This is reflected in other examples as well – all along the same theme.
The word for kissing, nesheq, appears precisely 13 times in the Torah. Which matches the age at which Ishmael was circumcised (creating a divine connection). The same number also echoes the 13 Attributes of Mercy (also a special divine connection), and the 13 bulls offered on the festival of Sukkos, which is the holiday described the most as the holiday of “simcha” – of unification and connection between G-d and His People.
This understanding, of course, teaches us that G-d very much desires a relationship with us, analogous to the desire that a husband has for his wife.
P.S. G-d’s kaneh is mentioned 10 times, with Pinchas’ corresponding jealousy for G-d is mentioned 3 times – totaling 13 for the human-divine relationship. While the thirteen times marital jealousy is named are found only in the section describing the suspected wife, the sotah.
P.P.S. Other uses of this word are the jealousy the Philistines have of Avraham’s material wealth, the jealousy of Rachel for Leah, the brothers for Joseph, and Moshe mocking the idea that he should have exclusive access to divine prophecy. Moshe was all about maximizing the connection between G-d and His people.