بُلُوغُ الْمَرَامِ
Bulugh al-Maram 439
The Book of Prayer
وَعَنْ مُعَاذٍ - رضى الله عنه - قَالَ: { خَرَجْنَا مَعَ رَسُولِ اَللَّهِ - صلى الله عليه وسلم -فِي غَزْوَةِ تَبُوكَ، فَكَانَ يُصَلِّي اَلظُّهْرَ وَالْعَصْرَ جَمِيعًا, وَالْمَغْرِبَ وَالْعِشَاءَ جَمِيعًا } رَوَاهُ مُسْلِمٌ . [1] .
Narrated Mu'adh bin Jabal (RA): We went out with Allah's Messenger (ﷺ) on the Tabuk expedition, and he would offer Zuhr and 'Asr prayers together and Magbrib and 'Isha' prayers together. [Reported by Muslim].
Sunnah.com reference: Book 2, Hadith 353