ייִדישער מחשבֿה אויף משלי 22:14

It is customary to compare the unknown to the known in order to better understand the unknown. G-d is referred to in scripture as possessing limbs, although He is purely spiritual, in order to make some of His actions more comprehensible. "As a shepherd leads a flock" (Isaiah 40,11), or "Your heavens are the work of Your fingers" (Psalms 8,4). Rabbi Yudan stated, "Great is the power of the prophets who have described the power of the Almighty in human terms, as it is said in Daniel 8,16, "I heard a human voice" (a voice sounding like the voice of man). The right to describe the creation of man as a fusion of dust and spirit, a joining of matter and form, is also based on such considerations. The known is described in order to make it easier to understand the unknown or the less well known.

Rabbi Yannai in the opening Midrash quoted, simply wanted to tell us that the lesson taught by the spice merchant had already been taught by Solomon in Proverbs.