Surah Al-Insan 76:23

إِنَّا نَحْنُ نَزَّلْنَا عَلَيْكَ ٱلْقُرْءَانَ تَنزِيلًا

Indeed, it is We who have sent down to you, [O Muḥammad], the Qur’ān progressively.

Translation: Saheeh International

Tafsir

Assuredly We nahnu reiterates the subject of innā ‘assuredly for the purpose of emphasis; alternatively it is a separating pronoun have revealed the Qur’ān to you as a gradual revelation tanzīlan is the predicate of inna ‘assuredly’ in other words We have divided it into parts instead of not revealing it all at once.

Excerpt from Tafsir al-Jalalayn, commentary on 76:23, via Quran.com. The reader has the full commentary and 9 more tafsirs.