When God descended upon Mount Sinai to give the Torah, the mountain erupted with phenomena that defied nature. The Mekhilta de-Rabbi Ishmael pauses on the word "lightnings" in (Exodus 19:16)—berakim in Hebrew—and makes a startling observation: "one different from the other." The lightnings at Sinai were not uniform. Each bolt was unique, distinct from the one that came before and the one that followed.
Ordinary lightning in a thunderstorm repeats itself. Flash after flash, bolt after bolt, each one essentially the same phenomenon of electrical discharge. But the lightnings at Sinai were different. Each one carried its own character, its own message, its own aspect of divine revelation. The rabbis saw in this detail evidence that the Sinai event was entirely supernatural—not a particularly intense thunderstorm, but a theophany without parallel in the natural world.
The Mekhilta continues: "And a heavy cloud upon the mountain"—this was the arafel, the thick, impenetrable mist that shrouded the peak of Sinai. The text connects this cloud to (Exodus 20:18): "And Moses drew near to the arafel." While the people stood below, trembling at the lightnings and the sound of the shofar, Moses alone walked forward into the darkness. The arafel was not merely weather. It was the boundary between the human and the divine, a curtain of darkness that hid the presence of God from mortal sight.
Together, the unique lightnings and the thick darkness paint a picture of Sinai as a place where normal reality broke down. The mountain was simultaneously illuminated by supernatural light and shrouded in supernatural darkness. Moses entered the arafel and emerged with the Torah—carrying divine law out of a cloud that no other human being could penetrate.