Silsilat al-Ahadith al-Sahihah

Sayyiduna Abdullah bin Mas'ud (may Allah be pleased with him) says: The Messenger of Allah (peace and blessings of Allah be upon him) combined the Zuhr and Asr, and Maghrib and Isha prayers and offered them together. When he was asked about the reason, he said: "I have offered these prayers in this manner so that my Ummah does not fall into hardship."