Surah An-Nur 24:13

لَّوْلَا جَآءُو عَلَيْهِ بِأَرْبَعَةِ شُهَدَآءَ ۚ فَإِذْ لَمْ يَأْتُوا۟ بِٱلشُّهَدَآءِ فَأُو۟لَـٰٓئِكَ عِندَ ٱللَّهِ هُمُ ٱلْكَـٰذِبُونَ

Why did they [who slandered] not produce for it four witnesses? And when they do not produce the witnesses, then it is they, in the sight of Allāh, who are the liars.

Translation: Saheeh International

Tafsir

Why did they that is this band of accusers not produce four witnesses to it? who had witnessed it. And since they did not produce the witnesses those in God’s sight in His judgement they are liars in this matter.

Excerpt from Tafsir al-Jalalayn, commentary on 24:13, via Quran.com. The reader has the full commentary and 9 more tafsirs.