What is the meaning of "Holech b'Yashro Yerei Hashem"?
Rashi: One who goes in straightness, he fears Hashem.
R. Yonah: This teaches that honored fear comes from straightness. It is better than fear that comes from fear of punishment. We infer from the Seifa that one who fears, he honors Hashem via his fear. Therefore, it puts Bozeh opposite to one who fears. Fear from straightness is the fulfillment of Hashem's Mitzvos, for he remembers His grandeur, and he cannot transgress His mouth. This is honor and fear.
Malbim: Yashar is one whose Sechel goes straightly due to his nature. Yashar is the shortest line between two points. A Yashar goes with is Sechel in the short, straight path. Particular matters pertain to Binah. Man's Sechel, if it will not tilt to the side, it will constantly contemplate the Emes - "Asah ha'Elokim Es ha'Adam Yashar v'Hemah Vikshu Chishbonos Rabim" (Koheles 7:29). Hashem made man's Sechel to always attain Emes, also via Binah - contemplating to know Emes and Sheker, and Elokus, that there is Elokim - a Creator who oversees, rewards and punishes
Why does it say "u'Nloz Derachav Bozehu"?
Rashi: One who makes his paths crooked, he disgraces Hashem.
R. Yonah: One whose Midos are estranged, he never has full fear of Hashem.
Malbim: One who departs from straightness, and seeks many calculations and misleading philosophical comparisons - he left the short straight line and goes off his path. He will come to denial in all cornerstones [of Emunah]. He disgraces Him, for he will deny Hashgachah and such matters.
