In Az-Zumar 39:55 ⧉, it was said: وَاتَّبِعُوا أَحْسَنَ مَا أُنزِلَ إِلَيْكُم (and follow the best of what has been sent down to you). The second phrase أَحْسَنَ مَا أُنزِلَ (the best of what has been sent down) means the Qur'an, and the whole Qur'an is but ahsan, the best - and the Qur'an can be called: اَحسَںَ و اکمل (best) also in the sense that out of all scriptures - Torah, Injil, Zabur - revealed from Allah Ta’ ala, the Qur'an is the best and the most perfect. (Qurtubi)