[Machine] The Messenger of Allah, ﷺ , said: The combination of the prayers without a valid excuse is considered a major sin. This statement is from the narration of Nuaim. And in the narration of Ya'qub, whoever combines the prayers without a valid excuse has committed one of the major sins. Husayn ibn Qais Abu Ali Al-Rahbi, known as Hanash, singled out this narration and used it, but he is weak according to the scholars of narration and his report cannot be relied upon.  

قَالَ رَسُولُ اللهِ ﷺ الْجَمْعُ بَيْنَ الصَّلَاتَيْنِ مِنْ غَيْرِ عُذْرٍ مِنَ الْكَبَائِرِ لَفْظُ حَدِيثِ نُعَيْمٍ وَفِي رِوَايَةِ يَعْقُوبَ مَنْ جَمَعَ بَيْنَ الصَّلَاتَيْنِ مِنْ غَيْرِ عُذْرٍ فَقَدْ أَتَى بَابًا مِنْ أَبْوَابِ الْكَبَائِرِ تَفَرَّدَ بِهِ حُسَيْنُ بْنُ قَيْسٍ أَبُو عَلِيٍّ الرَّحَبِيُّ الْمَعْرُوفُ بِحَنَشٍ وَهُوَ ضَعِيفٌ عِنْدَ أَهْلِ النَّقْلِ لَا يُحْتَجُّ بِخَبَرِهِ