The Zohar teaches that prior to the sin of eating from the tree of knowledge, the serpent was known merely as the letter “chet.” After it successfully enticed Chava to sin, Adam added to its name the letter “nun” from God’s name of Lordship (Ado-noy) and the letter “shin” from God’s name Sha-dai, calling it “nachash” to mitigate its potential to bring evil into the world. Similarly, the accusing angel was initially known by the letters “samech-mem,” but to counteract its wicked powers Adam added one of God’s names and called it Sama’el.
The Meged Yosef writes in the name of his grandfather, the mystic Rabbi Leib Sarah’s, that for a time Adam’s plan worked successfully. The additions from the Divine names kept the evil powers in check, and the world functioned reasonably for nine generations, but in the generation of Noach the world was filled with chamas – robbery. They sinned so greatly that they allowed the serpent and the prosecuting angel to regain their initial strength, as chamas is a combination of their original names (samech and mem).
In order to restore justice to the world, God had no choice but to once again diminish the power of this dastardly duo. He commanded Noach to make an ark which would measure 300 cubits long, 50 cubits wide, and 30 cubits tall, with the roof of the ark sloping upward to one cubit so that the rain would run off. Although one could mistakenly view these dimensions as arbitrary, the Meged Yosef explains the depth and precision of every detail in the Torah.
As each letter in the Hebrew alphabet has a numerical value, we may re-express the dimensions of the ark as shin cubits in length, nun cubits in width, lamed cubits in height, and an aleph cubit finish on the roof. The length and width are precisely the two letters needed to once again transform the I>chet back into nachash, while the height and the finish on top are exactly what were needed to reduce the mighty samech-mem into Sama’el. The ark which was built with these dimensions allowed Noach to combat the “chamas” which was rampant in his generation and be saved from the flood brought to destroy it.
by Rav Ozer Alport