YHVH said to Moses as follows:
Speak to the Israelite people and instruct them to make for themselves fringes on the corners of their garments throughout the ages; let them attach a cord of blue to the fringe at each corner…
— Bamidbar/Numbers 15:37-38, The Torah: A Women’s Commentary
We have been taught that R. Meir used to say: Why is blue different from all other colors? Because blue is similar to the color of the sea; the color of the sea is similar to the color of the firmament; the color of the firmament is similar to the color of sapphire; and the color of sapphire is similar to the color of the throne of glory, as it is said, “There was under His feet the like of paved work of sapphire stone, and the like of the very heaven for clearness” (Exod. 24:10); and also, “The semblance of a throne in appearance like sapphire” (Ezek. 1:26)
It is not obvious from the English, and so important to note, that the same Hebrew letters which make up the word, “sapphire,” samech-pei-reish, also make up the verb, “count/recount.” The word, “countable,” for example — samech-fei-yod-reish — differs from “sapphire” only in that the samech is vocalized with slightly different short “a” sounds: patach for the former; kamatz for the latter.
I first discovered this midrash through a note, by Arthur Green, to Psalm 19 in the Siddur Kol Haneshamah:
Ha-shamayim mesaperim k’vod-el. The skies recount the glory of divinity. The Hebrew verb mesaperim (“recount”) is associated by the rabbis with the word “sapphire.” The verse would then mean, “The heavens shine like sapphire with the glory of God.” (see also, “(Re)Counting: Amichai’s Perfect Rest” concerning Psalm 19.
Sefer Ha-Aggadah, Sefer Ha-Bloggadah
The fuller explanation, recounted in The Book of Legends, is taken from Sot 17a in the Babylonian Talmud and Ber 1:5, 3a in the Palestinian Talmud.)
Sefer Ha-Aggadah (The Book of Legends) is a compendium of material from the Talmud and later midrashic sources. It’s enormous — 902 oversize pages in the English edition — and far-ranging, using sources that span centuries, countries and viewpoints. It was originally published in then-nascent modern Hebrew by Hayim Nahman Bialik and Yehoshua Hana Ravnitzky in 1908 to help launch Hebrew’s revival.
This is a great resource, available from libraries and used booksellers. It’s worth perusing, section by section — “Israel in the Wilderness,” “Deeds of the Sages,” “The Community, the State and Their Requirements,” e.g. — or searching by means of the topical index and/or index of biblical passages. Specifics of publication in Source Materials.
Participants in the National Havurah Committee’s summer institute launched a page-a-day study of this book, “Sefer Ha-Bloggadah,” to take place over two years. Previous discussions (which do not yet reach the passage cited above) and an explanation of the project are available on-line.
The first year’s study culminates this summer  with a class at the Institute. Future study will continue on-line.
The “Opening the Book” series was originally presented in cooperation with the independent, cross-community Jewish Study Center and with Kol Isha, an open group that for many years pursued spirituality from a woman’s perspective at Temple Micah (Reform). “A Song Every Day” is an independent blog, however, and all views, mistakes, etc. are the author’s.