Surah Al-Kahf 18:7

إِنَّا جَعَلْنَا مَا عَلَى ٱلْأَرْضِ زِينَةً لَّهَا لِنَبْلُوَهُمْ أَيُّهُمْ أَحْسَنُ عَمَلًا

Indeed, We have made that which is on the earth adornment for it that We may test them [as to] which of them is best in deed.

Translation: Saheeh International

Tafsir

Truly We have made all that is on the earth in the way of animals plants trees rivers and so on as an adornment for it that We may try them that We may test mankind observing thereby which of them is best in conduct therein that is to see which of them is the most abstemious of it.

Excerpt from Tafsir al-Jalalayn, commentary on 18:7, via Quran.com. The reader has the full commentary and 9 more tafsirs.