Allah says,

﴿إِنَّ هَـذِهِ﴾

(Verily, this) meaning, this Surah.

﴿تَذْكِرَةٌ﴾

(an admonition,) meaning, men of understanding receive admonition from it. Thus, Allah says,

﴿فَمَن شَآءَ اتَّخَذَ إِلَى رَبِّهِ سَبِيلاً﴾

(therefore whosoever wills, let him take a path to His Lord.) meaning, from those whom Allah wills that they be guided. This is similar to the stipulation that Allah mentions in another Surah,

﴿وَمَا تَشَآءُونَ إِلاَّ أَن يَشَآءَ اللَّهُ إِنَّ اللَّهَ كَانَ عَلِيماً حَكِيماً ﴾

(But you cannot will, unless Allah wills. Verily Allah is Ever All-Knowing, Al-Wise.) (76:30)