What is the meaning of "Pesach Devarecha Ya'ir"?
Rashi #1: The beginning of Your words enlightened the heart of Yisrael - "You make the simple understand." You said "Anochi Hashem Elokecha Asher Hotzeisicha" (Shemos 20:2). You informed them that You acquired them from Beis Avadim in order to be Master over them. They must accept Your Elokus over them - "Lo Yihyeh Lecha Elohim Acherim..." (ibid., 3), and afterwards You decreed Your decrees.
Rashi #2: The beginning of Your words enlighten - Your first words in Ma'ase Bereishis were "Yehi Ohr" (Bereishis 1:3).
Radak: The beginning of Your words enlightens the eyes of those with a blind heart. When one begins to contemplate them, and puts his heart to them, his eyes will be enlightened and he will contemplate more 1 .
Malbim: They are unlike the parables of the early nations; their exterior is folly and fabricated stories without any benefit. Your words are different; also the simple meaning of the tales via which one enters Your words, also they enlighten. One learns from them Emunah, Musar and conduct.
Radak: Because David said "Pela'os Edvosecha" (129), he said also this, lest one slacken, and say 'since they are hidden, I cannot contemplate them.' Rather, he should begin to contemplate them, and they will open for him a way of understanding.
What is the meaning of "Mevin Pesayim"?
Rashi: Refer to 119:130:1:1.
Shemos Rabah 1 50:1: From there (the beginning of the Torah), Tzadikim will understand that when we begin a matter, we begin with its light. When Hashem told Moshe to build the Mishkan, Betzalel said, with what will we begin? With its light - "v'Asu Aron" (Shemos 25:10).
Malbim: Also the simpleton who does not understand Chachmah, he understands Musar and Da'as from tales of the Torah.
Tanchuma Vayakhel 7 is very similar. It seems that Rashi cites them, but there are printing mistakes. (PF)
