In The Name of Allaah, The Most Merciful, The Bestower of Mercy.
Allaah [The Most High] said:
وَمَن يَكْسِبْ خَطِيئَةً أَوْ إِثْمًا ثُمَّ يَرْمِ بِهِ بَرِيئًا فَقَدِ احْتَمَلَ بُهْتَانًا وَإِثْمًا مُّبِينًا
And whoever earns a fault or a sin and then throws it on to someone innocent, he has indeed burdened himself with falsehood and a manifest sin. [Surah An-Nisaa. Aayah 112]
Be warned against Fujoor Fil Khusoomah [Iniquity when disputing]! Imaam Muhammad Ibn Saaleh Al-Uthaymeen [rahimahullaah] said, ‘’Iniquity when disputing is of types: To claim what one is not entitled to and reject what is obligatory upon him [to fulfil, give etc]’’.
[Sharh Riyaadus Saaliheen 4/49-50]