This is probably the post you were looking for: What are easy examples from daily life of constrained optimization?
The story is true! In Section 6.4 (Arachim Vacharamim) of the Mishneh Torah, verse 8:4 states
When does the above apply? When they retracted one after the other. If, however, they all retracted at the same time, we divide the sum among them.
What is implied? The first one says: "I will [redeem] it for ten selaim," the second: "...for twenty," and a third "...for 24," and the second and third retract at the same time, we enable the first to redeem it for ten and we expropriate seven from the property of both the second and the third.10 Thus the Temple treasury collects 24. Similarly, if all three of them retract and the consecrated article is [ultimately] sold for three, we expropriate seven selaim from the property of all of them. These principles are followed in all instances.
This is a "prelude" to the constrained equal losses problem. Aumann and Maschler (1985)1 provides a much greater exposition including both Maimonides' stance and his intellectual adversary Rabad.
Reference
[1] Aumann, R. J., Maschler, M. (1985). Game theoretic analysis of a bankruptcy problem from the Talmud. Journal of Economic Theory. 36(2):195-213.