Lamed is the twelfth letter of the alphabet and its value is thirty. It has no final form. Its name is spelled lamed, mem, dalet: the same letters as the verb lamad, to learn.
In Sefer Yetzirah, lamed is one of the twelve simple letters, peshutot, beside the three mothers and the seven doubles, which are pronounced in two ways. The book gives the twelve simples twelve foundations, from sight to sleep, and places them at the twelve diagonal edges of space, which it calls "the arms of the world." For lamed it writes: "He made the letter lamed king, He bound a crown to it," and formed through it the Scales in the world, the month of Tishrei in the year and the liver in the soul. The same book sorts the letters by the part of the mouth that pronounces them: lamed belongs to the group dalet, tet, lamed, nun, tav, the letters of the tongue.
The Talmud relates that the Sages said to Rabbi Yehoshua ben Levi: children came today to the study hall and said things that were not said even in the days of Joshua son of Nun. They read the alphabet in pairs. After the lesson of the gimel running after the dalet, the poor man, they continue: "if you act this way," the Holy One, blessed be He, feeds you, zan (zayin), shows you favor, chan (chet), does you good, meitiv (tet), gives you an inheritance, yerushah (yod), and binds for you a crown, keter, for the World to Come, la'olam haba: kaf and lamed. Lamed thus closes the chain of promises.
The Alphabet of Rabbi Akiva offers two further readings. In the first: "do not read lamed, but lev mevin da'at," a heart that understands knowledge; and the text teaches that the heart weighs as much as all the limbs, for like a person it sees, hears, speaks, cries out and walks. In the second, Rabbi Akiva tells that the twenty-two letters were engraved with a pen of flame on the crown of the Holy One, blessed be He; when He wished to create the world they came down, and each one asked: create the world through me. Lamed pleaded: through me You will give Israel the tablets of the covenant and teach them the ten commandments. The answer was no: those tablets would be broken at the foot of the mountain, and the words would fly away from them. And lamed went out, downcast.
The sources weave around lamed a single thread, that of study: a name that is the verb to learn, a heart that understands, the tablets and the ten commandments, and for the children of the study hall, the crown of the World to Come. One can also keep the lesson of the refusal: even the tablets, the work of G-d, could be broken; what is learned must descend into the heart so that it does not fly away.
