What path looks straight, but its end is the way of death?
Rashi #1: He transgresses, and says that there is no sin.
Rashi #2: An Atzel's path is straight in the eyes of Esav, who is called "Ish [Sadeh]" (Bereishis 25:27); its end is death.
R. Yonah (16:25): Here it refers to laughter and Simchah. It appears Kosher and permitted, but its end is the way of death, like the coming verse explains "Gam bi'Schok Yich'av Lev."
Malbim: Sometimes a path seems straight to an Evvil, for it looks straight at the beginning. This is unlike the path of Chachmah, which appears to pass over thorns, for one must fight against desire and Midos of the Nefesh that lean towards evil. "Derech Evvil Yashar b'Einav" (12:15), but its end is death and destruction. In contrast, Derech Chachmah, its beginning is thorns, but its end is straight.
Ma'alos ha'Torah (DH b'Derech): Even when one approaches death due to bodily weakness, he should engage in Torah. 'One should never abstain from the Beis Medrash and words of Torah, even at the time of death -- "Zos ha'Torah Adam Ki Yamus b'Ohel" (Bamidbar 19:14) (Shabbos 83b).
