Imam Khomeini’s explanation of the 'straight path' was that how Satan desperately attempts faithful people go astray by using vicious designs and snares
Imam cited the following verse from the holy Quran
"Then is one who walks fallen on his face better guided or one who walks erect on a straight path?" Quran 67,22
Imam further explained that God Almighty has presented a parable in this noble verse of those who turned away from the guardianship (vilayat) of the Commander of the Faithful (Imam Ali ('a).
It seems as if they were walking with their own faces and would not be guided.
And those who follows Imam 'Ali ('a), the truthful successor the holy prophet of Islam, have been righty placed on a straight path which is associated with following of the Commander of the Faithful.
(An exposition on Forty Hadith, p. 533)
http://en.imam-khomeini.ir/en/n51893/The-Supplication-for-the-4th-Day-of-Ramadan