The Messenger of Allah ﷺ said, "Allah said, 'The son of Adam has denied Me, though he had no right to do so, and he has insulted Me, though he had no right to do so. As for his denial of Me, it is his saying that I will not bring him back to life as I first created him. As for his insult against Me, it is his saying that Allah has taken a son, while I am the Eternal, who did not beget and was not begotten, and there is none equal to Me.'""He neither begets nor is born, nor is there to Him any equivalent" [Ikhlas 112:3–4].The words kufuwan, kafian, and kifaan all carry the same meaning.
حدثنا إسحاق بن منصور قال وحدثنا عبد الرزاق أخبرنا معمر عن همام
قال رسول الله ﷺ قال الله كذبني ابن آدم ولم يكن له ذلك وشتمني ولم يكن له ذلك أما تكذيبه إياي أن يقول إني لن أعيده كما بدأته وأما شتمه إياي أن يقول اتخذ الله ولدا وأنا الصمد الذي لم ألد ولم أولد ولم يكن لي كفؤا أحد {لم يلد ولم يولد ولم يكن له كفؤا أحد} كفؤا وكفيئا وكفاء واحد