Ibn Hibban

Sayyiduna Mu’adh bin Jabal (may Allah be pleased with him) narrates: On the occasion of the Battle of Tabuk, when the Prophet (peace and blessings be upon him) intended to depart before the sun had declined, he would delay the Zuhr prayer until he combined it with the Asr prayer, and he would perform both prayers together. And when he intended to depart after the sun had declined, he would perform the Zuhr and Asr prayers together and then set out. Similarly, when he intended to depart before Maghrib, he would delay the Maghrib prayer until he performed it together with the Isha prayer, and when he intended to depart after Maghrib, he would perform the Isha prayer early and combine it with the Maghrib prayer. I heard Muhammad bin Ishaq Thaqafi say: I heard Qutaybah bin Sa’id say: There are seven hadith memorisers who have marked this hadith from me (they are): Ahmad bin Hanbal, Yahya bin Ma’in, Humaydi, Abu Bakr bin Abu Shaybah, Abu Khaythamah, until he counted seven individuals.