Idle talk لغو

In a dream, hearing it signifies disobedience and refusal to accept advice, because of His saying, the Exalted:

وَإِذَا سَمِعُوا۟ ٱللَّغْوَ أَعْرَضُوا۟ عَنْهُ وَقَالُوا۟ لَنَآ أَعْمَـٰلُنَا وَلَكُمْ أَعْمَـٰلُكُمْ سَلَـٰمٌ عَلَيْكُمْ لَا نَبْتَغِى ٱلْجَـٰهِلِينَ

“And when they hear ill speech, they turn away from it and say, "For us are our deeds, and for you are your deeds. Peace will be upon you; we seek not the ignorant."”

Quran 28:55 · Saheeh International

Unintentional oaths [laghw, the same word] signify repentance for the sinner and the unbeliever's embracing Islam, because of His saying, the Exalted:

لَّا يُؤَاخِذُكُمُ ٱللَّهُ بِٱللَّغْوِ فِىٓ أَيْمَـٰنِكُمْ وَلَـٰكِن يُؤَاخِذُكُم بِمَا كَسَبَتْ قُلُوبُكُمْ ۗ وَٱللَّهُ غَفُورٌ حَلِيمٌ

“Allāh does not impose blame upon you for what is unintentional in your oaths, but He imposes blame upon you for what your hearts have earned. And Allāh is Forgiving and Forbearing.”

Quran 2:225 · Saheeh International