Surah Ya-Sin — Ayah 39 (36:39)
وَٱلۡقَمَرَ قَدَّرۡنَٰهُ مَنَازِلَ حَتَّىٰ عَادَ كَٱلۡعُرۡجُونِ ٱلۡقَدِيمِ ٣٩
English translation (Saheeh International)
And the moon - We have determined for it phases, until it returns [appearing] like the old date stalk.
Brief commentary
A sign for them indicating His Oneness, (may He be glorified), is this moon for which I have determined phases each night. It begins small then becomes big and then small again until it becomes similar to a twisted, old date stalk, in it appearing as thin, curved, yellow and old.