"إن هذه"، أي: آيات القرآن "تذكرة"، تذكير وموعظة، "فمن شاء اتخذ إلى ربه سبيلاً"، بالإيمان والطاعة.
This admonition - containing an exposition of the horror and severity of the day of judgment - is a reminder that is of benefit to the believers. So whoever wishes to take a path that leads to His Lord let him do so.