Tafsir of Surah Al-Maaida 5:73
﴿لَّقَدْ كَفَرَ الَّذِينَ قَالُوا إِنَّ اللَّهَ ثَالِثُ ثَلَاثَةٍ وَمَا مِنْ إِلَٰهٍ إِلَّا إِلَٰهٌ وَاحِدٌ وَإِن لَّمْ يَنتَهُوا عَمَّا يَقُولُونَ لَيَمَسَّنَّ الَّذِينَ كَفَرُوا مِنْهُمْ عَذَابٌ أَلِيمٌ﴾
Translation of the meaning
They have certainly disbelieved who say, "Allāh is the third of three." And there is no god except one God. And if they do not desist from what they are saying, there will surely afflict the disbelievers among them a painful punishment.
English Translation - Noor International Center — v1.1.2 · QuranEnc.comThe words of the two imams are given in their original Arabic, verbatim, with references.
Shaykh al-Islam Ibn Taymiyyah
وقد أخبر سبحانه عقب قوله {ثالث ثلاثة} بما يقتضي أن هؤلاء اتخذوه ولدا بقوله: {ولا تقولوا ثلاثة انتهوا خيرا لكم إنما الله إله واحد سبحانه أن يكون له ولد}.«التسعينية» 3/854