Surah Al-Anbya 21:5

بَلْ قَالُوٓا۟ أَضْغَـٰثُ أَحْلَـٰمٍۭ بَلِ ٱفْتَرَىٰهُ بَلْ هُوَ شَاعِرٌ فَلْيَأْتِنَا بِـَٔايَةٍ كَمَآ أُرْسِلَ ٱلْأَوَّلُونَ

But they say, "[The revelation is but] a mixture of false dreams; rather, he has invented it; rather, he is a poet. So let him bring us a sign just as the previous [messengers] were sent [with miracles]."

Translation: Saheeh International

Tafsir

Nay bal in the three instances below effects a transition from one subject to another but they say regarding those parts of the Qur’ān he the Prophet has brought to them are ‘A muddle of nightmares a confusion of things he has seen in his sleep. Nay he has fabricated it he has invented it; …

Excerpt from Tafsir al-Jalalayn, commentary on 21:5, via Quran.com. The reader has the full commentary and 9 more tafsirs.