Surah Al-Kahf 18:109

قُل لَّوْ كَانَ ٱلْبَحْرُ مِدَادًا لِّكَلِمَـٰتِ رَبِّى لَنَفِدَ ٱلْبَحْرُ قَبْلَ أَن تَنفَدَ كَلِمَـٰتُ رَبِّى وَلَوْ جِئْنَا بِمِثْلِهِۦ مَدَدًا

Say, "If the sea were ink for [writing] the words of my Lord, the sea would be exhausted before the words of my Lord were exhausted, even if We brought the like of it in [continual] supplement."

Translation: Saheeh International

Tafsir

Say ‘If the sea in other words if its waters were ink midād is what one writes with for the Words of my Lord Words that testify to His laws and His marvels such that these Words are written with it the sea would be spent in recording them before the Words of my Lord were spent read as tanfada or yanfada even though We …

Excerpt from Tafsir al-Jalalayn, commentary on 18:109, via Quran.com. The reader has the full commentary and 9 more tafsirs.