Name the battle in which Hazrat Khalid bin Waleed (RA) participated for the first time?

The correct answer is the Battle of Motta (also known as the Battle of Mu'tah).

The Catalyst for Conflict

The expedition was triggered by a grave diplomatic provocation. The Prophet Muhammad (SAW) had sent Harith bin Umayr al-Azdi (RA) as an envoy to the ruler of Busra. However, while passing through the region of Mu'tah (located in modern-day Jordan), the envoy was intercepted and executed by Shurahbil bin Amr al-Ghassani, a governor under the Byzantine Empire. In the geopolitical traditions of the time, the killing of an envoy was considered a declaration of war. In response, a Muslim army of 3,000 men was dispatched from Medina to the north.

The Chain of Command

Before the army departed, the Prophet (SAW) established a unique succession of leadership, which was a departure from standard practice. He appointed Zaid bin Harithah (RA) as the commander, stating that if Zaid were to fall, Jafar bin Abi Talib (RA) would take the standard, and if Jafar were martyred, Abdullah bin Rawahah (RA) would take command. This foresight proved critical as the 3,000-strong Muslim force arrived in Mu'tah only to find themselves facing a massive coalition force of Byzantines and Ghassanids, estimated by many historians to be nearly 100,000 to 200,000 soldiers.

The Heroism at Mu'tah

The battle was fierce and lopsided in terms of numbers. As the conflict raged, all three appointed commanders were martyred in the order the Prophet (SAW) had predicted. In the vacuum of leadership that followed, the Muslim soldiers quickly consulted one another. Thabit bin Aqram (RA) took the banner and handed it to Khalid bin Waleed (RA), citing his superior military experience. Though Khalid had only recently embraced Islam, his tactical genius was already well-known.

Khalid bin Waleed (RA) faced a nearly impossible situation. The Muslim army was exhausted and surrounded by a significantly larger force. To prevent a total massacre, Khalid employed a brilliant psychological tactic. Under the cover of night, he restructured his lines, moving the right wing to the left and the left to the right, and bringing the rear guard to the front. He also ordered a group of soldiers to ride behind the hills to stir up clouds of dust.

The Tactical Retreat and "Saifullah"

When the sun rose, the Byzantine forces saw "new" faces and massive dust clouds, leading them to believe that significant reinforcements had arrived from Medina. Fearing a fresh onslaught, the Byzantines hesitated. Khalid seized this moment of confusion to execute a disciplined and strategic retreat, withdrawing the Muslim forces safely back toward Medina.

Upon the army's return, the Prophet (SAW) described the battle to the people in Medina, even before the soldiers had arrived. He informed the companions of the martyrdom of the three leaders and noted that the "Sword of Allah" (Saifullah) had eventually taken the standard and achieved a breakthrough. This was the moment Khalid bin Waleed (RA) received his eternal title, marking the beginning of a military career that would see him remain undefeated in over a hundred battles.