Midrash sur La Genèse 28:14

And the Lord appeared unto him by the terebinths of Mamre (Gen. 18:1) May it please our master to teach us: How many benedictions must a man pray each day? Thus do our masters teach us: A man must pray the eighteen benedictions (of the Amidah) each day. Why eighteen? R. Samuel the son of Nahman stated: This number corresponds to the eighteen instances in which the names of the patriarchs are mentioned simultaneously in the Torah.¹Cf. Y. Berakhot 84c, Y. Taanit 82b. The first being: And God will surely remember you, and bring you out of this land to the land which he swore to Abraham, to Isaac, and to Jacob (Gen. 50:24), and the last: The Lord said to me: This is the land which I swore unto Abraham, unto Isaac, and unto Jacob (Deut. 34:4). However, if someone should insist that the patriarchs are actually mentioned nineteen times, since it is written: God of Abraham thy father, and the God of Isaac; the land whereon thou liest, to thee will I give it (Gen. 28:13), inform him that this verse is not counted, since Jacob’s name is not included (in the verse).

2) "Then I shall give your rains in their proper times": (but) not the rains of all the lands. How, then, am I to understand (Bereshith 28:14) "And all the families of the earth will bless themselves in you and in your seed"? That there will be plenty in Eretz Yisrael and famine in all the lands. And they will come and buy from you and enrich you with money, as it is written (Bereshith 47:14) "And Yosef gathered in all the money that was found in the land of Egypt and in the land of Canaan for the food that they bought." And (Devarim 33:25) "As your days, your flow" — All of the lands will "flow" money and bring it to Eretz Yisrael.

(Exod. 30:12): WHEN YOU TAKE <A CENSUS>. R. Joshua bar Nahmani the Priest said: The Holy One said to Moses: Go and number Israel.¹⁶PRK 2:8; Tanh., Exod. 9:1. Moses said to the Holy One: It is written (in Gen. 28:14): AND YOUR SEED SHALL BE LIKE THE DUST OF THE EARTH…; (and in Hos. 2:1 [1:10]): THE NUMBER OF THE CHILDREN OF ISRAEL SHALL BE AS THE SAND OF THE SEA…. So are you saying: Go and number Israel! Moses said to the Holy One: I am unable to hold out in counting them. The Holy One said to him: Moses, it is not as you think. However, if you wish to hold out in counting Israel, take the initial letters of the tribes. Then you shall hold out in counting them. <Take> the resh from Reuben, the shin from Simeon, the lamed from Levi, etc., for each and every tribe. To what is the matter comparable? To a money-changer who had a boy. He said to him: Count these coins for me. He said to him: How can I count them? He said to him: count the tops of the stacks of coins, and you will hold out in the calculation. So when Moses met with difficulties in the calculation of Israel, the Holy One said to him: Take the initial letters of the tribes, and you shall hold out in their calculation. The resh of Reuben equals two hundred thousand;¹⁷This and the following numbers comprise numerical equivalents of the initial Hebrew letters times one thousand. the nun of Naphtali equals fifty thousand; the shin of Simeon equals three hundred thousand; the yod of Judah <plus> the yod of Joseph <plus> the yod of Issachar equal thirty thousand; the zayin of Zebulun equals seven thousand; the dalet of Dan equals four thousand; the gimel of Gad equals three thousand; the bet of Benjamin equals two thousand; the alef of Asher equals one thousand. The result is five hundred ninety-seven thousand. Where are the three thousand (from the original six hundred thousand of Exod. 12:37)? These were the ones who fell in the days of the <golden> calf, as stated (in Exod. 32:28): SO THE CHILDREN OF LEVI ACTED ACCORDING TO THE WORD OF MOSES, AND ABOUT THREE THOUSAND OF THE PEOPLE FELL ON THAT DAY. For that reason the Holy One said to Moses: Number Israel in order to know how many are missing.