Ibn Kathir (Abridged)
Hafiz Ibn Kathirوَهَـذَا صِرَطُ رَبِّكَ مُسْتَقِيماً(And this is the path of your Lord leading straight.) that is, Islam, that We have legislated for you, O Muhammad, by revealing this Qur'an to you, is Allah's straight path. قَدْ فَصَّلْنَا الآيَـتِ(We have detailed Our Ayat...) We have explained the Ayat and made them clear and plain, لِقَوْمٍ يَعْلَمُونَ(for a people who take heed) those who have sound comprehension and understand what Allah and His Messenger convey to them, لَهُمْ دَارُ السَّلَـمِ(For them will be the abode of peace) Paradise, عِندَ رَبِّهِمْ(with their Lord.) on the Day of Resurrection. Allah described Paradise as `the abode of peace', because its residents are safe due to their access to the straight path, which conforms to the way of the Prophets. And just as their way was not wicked, they earned the abode of peace which is free from all wickedness.
وَهُوَ وَلِيُّهُم(And He will be their Wali) Protector, Supporter and Helper, بِمَا كَانُواْ يَعْمَلُونَ(because of what they used to do,) As reward for their good deeds, Allah has favored them and been generous with them, and awarded them Paradise.