The first expedition to banu Thalabah was as a result of this tribe’s continued hostilities. Unfortunately, while Muhammad Ibn Maslama was sent to the area where the enemy was, they were ambushed from every side. All the Muslims were killed, only Muhammed Ibn Maslamah escaped alive.
Now, the second expedition was sent out under the command of Abu Ubaydah bin al-Jarrah to look for the criminals who had murdered many Muslims. Upon Abu Ubaydah bin al-Jarrah reaching where the criminals resided, the enemy fled into the mountains (another reports says the enemy was no where to be seen and the companions returned to Madinah).
Kitab al-tabaqat al-kabir – Ibn Sa’d:
“… The Apostle of Allah despatched Muhammad Ibn Maslamah with ten men towards Banu Thalabah and Banu Awal, a branch of Banu Thalabah who were at Dhu al-Qassah, lying at a distance if twenty four miles from al-Madinah on the route of Rabadhah, They arrived thee at night. The enemy had one hundred men.
They surrounded them. They (parties) exchanged arrows for an hour in the night then al-A’rab (Bediouns) attacked them with spears and killed them. Muhammed Ibn Maslamah fell wounded. His ankle was injured so he could not move. They stripped them off their clothes, Then a Muslim passed by Muhammad Ibn Maslamah.
He bore him to Madinah. Then the Apostle of Allah despatched Abu Ubaydah ibn al-Jarrah with forty men to the site of people’s encounter. There they found no one … and returned.” 
“In this year the Messenger of God sent out Muhammad b. Maslamah with ten men in Rabi’i. The enemy lay wait for them until he and his companions went to sleep. Before they suspected anything, there was the enemy. The companions of Muhammad b. Maslamah were killed; Muhammad escaped wounded. …
In this year the Messenger of God dispatched the raiding party of Abu Ubaydah b. al-Jarrah to Dhu al-Qassah in the month of Rabi’ II with forty men. They travelled through the night on foot and reached Dhu al-Qassah just before dawn. They raided the inhabitants, who escaped them by fleeing to the mountains. …” 
“In retaliation against Bani Tha’labah, Abu Ubaidah bin al-Jarrah, at the head of forty men, was despatched to Dhil Qassa. They walked that night and took the enemy by surprise in the morning. Again, they fled to the mountains except one who was injured, and later embraced Islam. …” 
 Kitab al-tabaqat al-kabir, by Ibn Sa’d, volume 2, page 105
 The History of al-Tabari: The Victory of Islam: Muhammad at Madinah, [Michael Fishbein – Translator] volume 8, page 93
 Sealed Nectar (‘Ar-Raheeq Al-Makhtum’), By Safiur-Rahman Al-Mubarakpuri, 147