Surah Ar-Rahman 55:37

فَإِذَا ٱنشَقَّتِ ٱلسَّمَآءُ فَكَانَتْ وَرْدَةً كَٱلدِّهَانِ

And when the heaven is split open and becomes rose-colored like oil -

Translation: Saheeh International

Tafsir

And when the heaven is split open when it becomes open with many gates in preparation for the descent of the angels and it turns crimson wardatan literally ‘a rose’ in other words red like this rose like tanned leather red skins in contrast to its the heaven’s usual appearance the response to idhā ‘when’ is along the …

Excerpt from Tafsir al-Jalalayn, commentary on 55:37, via Quran.com. The reader has the full commentary and 9 more tafsirs.