Torah is the blueprint of reality. Blue is the color of the sea, the sky, and the Throne of Glory. White – transcendence, blue – immanence.
Diamonds are white and sapphires are blue. In Hebrew, "diamonds and sapphires" = Israel.
Leah's 5th and 6th sons were Issachar and Zevulun. Their precious stones on the breastplate of the High Priest were sapphire and diamond.
"Sapphire" comes from "book." Issachar was a student of the book. Zevulun was a merchant. A good, honest merchant reaches transcendence.
The book is the blueprint, the sapphire. Merchants bring home diamonds from across the sea. Zevulun shares his profits with Issachar.
A good merchant utilizes every spare moment to learn Torah. He knows how beautiful diamonds and sapphires are together.
"Book" also means "story." The merchant has his story to tell, which he can best tell in the words of Torah.
Issachar plus Zevulun = 925, the 22nd inspirational number and the 25th pentagonal number. 22 – 4th pentagonal and 25 – 4th inspirational.
The average value of the first 25 pentagonal numbers is 325, the triangle of 25! The sapphire-diamond brothers cut their jewels as fives.
Issachar means "there is reward." Zevulun means "dwelling place." With Torah study comes reward; merchants create a dwelling place for God.
Merchants see Divine Providence more than students. "Merchant" means to revolve around and around; they see Providence from all sides.
The Rebbe Rashab said that every Jew is a precious diamond. You must examine him over and over to reveal his hidden beauty and brilliance.
Jew is short for jewel. Every human being has the potential to become a Jew or at least feel connected to the Jewish People.
Even a person born into Judaism (and observant as well) has to strive to become a Jew, to become one with God in thought, word, and action.