Joining Two Salah Without Any Reason
According to the holy Quran, saying the prayers at their prescribed times is obligatory. Concession to join the prayers is given for a valid reason. Therefore, it is not allowed to combine the prayers without a reason. The cited Asr of Ibn Abbas is his impression; he did not know the reason, it does not imply that there was no reason, because the Prophet could not go against the Quran. God says in the Quran: فَإِذَا اطْمَأْنَنتُمْ فَأَقِيمُوا الصَّلَاةَ ۚ إِنَّ الصَّلَاةَ كَانَتْ عَلَى الْمُؤْمِنِينَ كِتَابًا مَّوْقُوتًا And when you become secure, perform the regular Prayer. The Prayer is enjoined upon the believers at stated times.