Sayyiduna Anas bin Malik (may Allah be pleased with him) narrates: On the day of Yarmuk I reached Sayyiduna Thabit bin Qays bin Shammas (may Allah be pleased with him), and he had uncovered his thighs and was saying: "Like this, (clear the way) from in front of our faces, and we will strike the enemy. How evil is what you have accustomed your opponents to! By Allah, this is not how we used to fight alongside the Messenger of Allah (peace and blessings be upon him)."
Hadith Referenceالمعجم الكبير للطبراني / باب الثاء / 1309