Surah Al-Muzzammil 73:8

وَٱذْكُرِ ٱسْمَ رَبِّكَ وَتَبَتَّلْ إِلَيْهِ تَبْتِيلًا

And remember the name of your Lord and devote yourself to Him with [complete] devotion.

Translation: Saheeh International

Tafsir

And mention the Name of your Lord that is say bi’smi’Llāhi’l-rahmāni’l-rahīm ‘In the Name of God the Compassionate the Merciful’ to begin your recitation and devote yourself exclusively to Him with complete devotion tabtīlan is the verbal noun from batala used here instead of tabattulan in order to concord with the …

Excerpt from Tafsir al-Jalalayn, commentary on 73:8, via Quran.com. The reader has the full commentary and 9 more tafsirs.