In The Name of Allāh, The Most Merciful, The Bestower of Mercy.

The Messenger of Allāh, peace and blessings of Allāh be upon him, said: “Indeed Allah is pure and He does not accept, except that which is pure”.

Al-Allamah Salih Al Fawzan, may Allah preserve him, said:

In this hadith he, peace and blessings of Allāh be upon him, described Allāh, The Exalted, that He is pure. “Allah is pure”, meaning: Allah is free from all imperfections and deficiencies. He is pure in His Essence, His Names and Attributes, and His Commandments and Prohibitions. Allah is pure in every aspect and imperfection cannot reach Him. Due to this, Allah does not accept actions, statements and intentions except that which is pure. He does not accept filthy statements, actions and intentions. Allah does not accept except what is pure, as Allāh, The Most High, said:

إِلَيْهِ يَصْعَدُ الْكَلِمُ الطَّيِّبُ وَالْعَمَلُ الصَّالِحُ يَرْفَعُهُ
To Him ascend (all) the goodly words. [35:10]

Allah does not accept, except good speech and good actions. As for filthy speech, indeed Allah rejects and hates it, such as lies, backbiting, tale carrying, abuse, false speech and false testimony, and all filthy statements, (such as) shirk and kufr. All of this is filthy speech and does not ascend to Allah, and they are not accepted.

Al Minhatur Rabbaaniyyah Fee Sharh Arba’een An-Nawawiyyah’ page:133-134