Hisham bin Urwah (may Allah have mercy on him) says that his father (may Allah have mercy on him), Sa'id bin al-Musayyib (may Allah have mercy on him) and Abu Bakr bin Abd al-Rahman bin al-Harith bin Hisham bin al-Mughirah al-Makhzumi (may Allah have mercy on him), all of these men, would combine Maghrib and Isha on a rainy night, and they did not object to it.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الصلاة / 5557