על החוקים לפרטיהם, ספר ב ל׳On the Special Laws, Book II 30

א׳
1[176] The festival of the Sheaf, which has all these grounds of precedence,  indicated in the law, is also in fact anticipatory of another greater feast. For it is from it that the fiftieth day is reckoned, by counting seven sevens, which are then crowned with the sacred number by the monad,  which is an incorporeal image of God, Whom it resembles because it also stands alone. This is the primary excellence exhibited by fifty, but there is another which should be mentioned.
ב׳
2[177] One reason among others which makes its nature so marvellous and admirable is that it is formed by what the mathematicians tell us is the most elemental and venerable of existing things,  namely, the right-angled triangle. In length its sides are 5, 3, 4, of which the sum is twelve, the pattern of the zodiac cycle, the duplication of the highly prolific six, which is the starting-point of perfection since it is the sum of the factors which produce it through multiplication. But we find that the sides when raised to the second power, i.e. 3 × 3 + 4 × 4 + 5 × 5, make 50, so that we must say that 50 is superior to 12 in the same degree as the second power is superior to the first.
ג׳
3[178] And if the lesser of these is represented by the most excellent of the heavenly spheres, the zodiac, the greater, namely 50, must be the pattern of some quite superior form of existence. But a discussion of this would be out of place at this point. It is quite enough for the present to call attention to the difference, so as to avoid treating a prominent fact as of secondary importance.
ד׳
4[179] The feast which is held when the number 50 is reached has acquired the title of “first-products.”  On it it is the custom to bring two leavened loaves of wheaten bread for a sample offering of that kind of grain as the best form of food. One explanation of the name, “Feast of First-products,” is that the first produce of the young wheat and the earliest fruit to appear is brought as a sample offering before the year’s harvest comes to be used by men.
ה׳
5[180] It is no doubt just and a religious duty that those who have received freely a generous supply of sustenance so necessary and wholesome and also palatable in the highest degree should not enjoy or taste it at all until they have brought a sample offering to the Donor, not indeed as a gift, for all things and possessions and gifts are His, but as a token, however small, by which they show a disposition of thankfulness and loyalty to Him Who, while He needs no favours, sends the showers of His favours in never-failing constancy.
ו׳
6[181] Another reason for the name may be that wheaten grain is pre-eminent as the first and best product, all the other sown crops ranking in the second class in comparison; for as an archon in a city or a pilot in a ship are said to be the first because they regulate the course of the city or the ship, as the case may be, so wheaten grain has received the compound name of “first-product” because it is the best of all the cereals, which it would not be,  unless it were also the food used by the best of living creatures.
ז׳
7[182] The loaves are leavened in spite of the prohibition  against bringing leaven to the altar, not to produce any contradiction in the ordinances, but to ensure that so to speak there shall be a single kind, both for receiving and giving. By receiving I mean the thanksgiving of the offerers, by giving the immediate return without any delay to the offerers of what they bring, though not for their own use.
ח׳
8[183] For food that has once been consecrated will be used by those who have the right and authority, and that right belongs to those who act as priests who through the beneficence of the law have the right to partake of any thing brought to the altar which is not consumed by the undying fire—a privilege granted either as a payment for officiating or as a prize for the contests which they endure in the cause of piety, or a sacred allotment in lieu of land, in the apportionment of which they had not received their proper share like the other tribes.
ט׳
9[184] But leaven is also a symbol for two other things: in one way it stands for food in its most complete and perfect form, such that in our daily usage none is found to be superior or more nourishing, and as wheat-meal is superior to that of the other seed crops, its excellence demands that the offering made in recognition of it should be of the same high quality.
י׳
10[185] The other point is more symbolical. Everything that is leavened rises, and joy is the rational elevation or rising of the soul.  And there is nothing that exists which more naturally gives a man joy than the possession in generous abundance of necessaries. Such rightly call forth gladness and thanksgiving in those who by the leavened loaves give outward expression to the invisible sense of well-being in their hearts.
י״א
11[186] The offering takes the form of loaves instead of wheaten meal,  because when the wheat has come there is nothing still missing in the way of appetizing food. For we are told that of all the seed crops, wheat is the last to spring up and be ready for harvesting.
י״ב
12[187] And these thank-offerings of the best kind are two in number for the two kinds of time, the past and the future; for the past, because our days have been spent in abundance, free from the experience of the evils of want and famine; for the future, because we have laid by and prepared resources to meet it, and are full of bright hopes while we dispense and bring out for daily use the gifts of God as they are needed by the rules of good economy.