Surah An-Naml 27:1

طسٓ ۚ تِلْكَ ءَايَـٰتُ ٱلْقُرْءَانِ وَكِتَابٍ مُّبِينٍ

Ṭā, Seen. These are the verses of the Qur’ān [i.e., recitation] and a clear Book

Translation: Saheeh International

Tafsir

Tā sīn God knows best what He means by these letters. Those namely these signs are the signs of the Qur’ān signs from it and a Manifest Book manifesting what is truth from what is falsehood wa-kitābin ‘Book’ is a supplement to al-qur’ān with the addition of an adjective mubīn ‘manifest’.

Excerpt from Tafsir al-Jalalayn, commentary on 27:1, via Quran.com. The reader has the full commentary and 9 more tafsirs.