על החוקים לפרטיהם, ספר א כ״זOn the Special Laws, Book I 27

א׳
1[131] The priests were not allotted a section of territory by the law so that like the others they might reap the proceeds of the land and have abundance of their requisites therefrom. Instead, when referring to the consecrated offerings, it paid them the transcendent honour of saying that God was their inheritance.  He is their inheritance for two reasons. One is the supreme honour conferred by sharing with God in the thank-offering rendered to Him. The other is the obligation to concern themselves only with the sacred rites, thus becoming in a sense trustees of inheritances. The prizes and guerdons which the law offers are as follows.
ב׳
2[132] First, a maintenance ready to hand and entailing no labour or trouble. For he commands that from all dough of wheat or other grain,  the bakers should set apart a loaf as a first portion for the use of the priests. In this he is also thinking of the avenue to piety provided by the lesson which the law of setting apart gives to those who obey it.
ג׳
3[133] For through being accustomed to make this offering out of their necessary food, they will have God in indelible recollection and no greater blessing can be gained than this. As the nation is very populous, the first-fruits are necessarily also on a lavish scale, so that even the poorest of the priests has so superabundant a maintenance that he seems exceedingly well-to-do.
ד׳
4[134] Secondly, he ordains that first-fruits should be paid of every other possession; wine from every winepress, wheat and barley from every threshing-floor, similarly oil from olives, and fruits from the other orchard-trees, so that the priests may not have merely bare necessaries, just keeping themselves alive in comparatively squalid conditions, but enjoy abundance of the luxuries of life and pass their days amid cheerful and unstinted comfort in the style which befits their position.
ה׳
5[135] A third perquisite is the first-born males of all land animals suitable for the use and service of men.  These he orders to be distributed to the priests: in the case of kine and sheep and goats the actual offspring, male calves and lambs and kids, since they are “clean” for the purposes both of eating and sacrificing, and are recognized as such. For the others, horses and asses and camels and the like, compensation is to be paid without chaffering about the value.
ו׳
6[136] All these are very numerous, for the men of the nation are noted particularly as graziers and stock-breeders, and keep flocks and herds of goats and oxen and sheep and of every kind of animal in vast numbers.
ז׳
7[137] And this is not all. We find the laws carrying the principle to a further extent by commanding that first-fruits should be paid not only from possessions of every kind but also from their own souls and bodies. For children are separable parts of their parents, or rather to speak more truly, inseparable parts, joined to them by kinship of blood, by the thoughts and memories of ancestors, invisible presences still alive among their descendants, by the love-ties of the affection which unites them, by the indissoluble bonds of nature. 
ח׳
8[138] Yet even parents have their first-born male children consecrated as a first-fruit, a thank-offering for the blessings of parenthood realized in the present and the hopes of fruitful increase in the future. At the same time he shews his wish that the marriages, the first produce of which is a fruit sacred to His service, should be not only blameless but worthy of the highest praise. And reflection on this should lead both husbands and wives to cherish temperance and domesticity and unanimity, and by mutual sympathy shewn in word and deed to make the name of partnership a reality securely founded on truth.
ט׳
9[139] But to prevent the parents being separated from the children and the children from their parents, he assessed the first-fruit arising from the consecration of the first-born sons at a fixed sum of money, and ordered rich and poor to make the same contribution. He did not take into consideration either the dignity of the contributors or the good condition and beauty of the offspring, but fixed the payment at an amount which was within the power of even the very poor.
י׳
10[140] For since the birth of children is an event equally common with the grandest and the meanest, he considered it just to enact that the contribution should be equal also, aiming, as I have said, as nearly as possible at a sum within the means of all.