Behold! Lord Allah promised you one of the two groups that it should be yours; you wished to face the unarmed group. But Allah Willed to testify the Truth with His Word and to cut the taproot of the disbelievers.
One of the groups was the unarmed trade group having 40 security guards under the leadership of Abu-Sufiyan who were returning from Syria to Mecca after their trade. The other group was from Mecca having about 1000 soldiers of vehement for saving the trade group under the leadership of Abu-Jahil. The weakling believers who were following the Messenger with hesitation wished to face the unarmed small trade group. But Lord Allah Willed to cut off the taproot of disbelievers by attacking the large armed force of disbelievers with His small Party of believers; thus, to give Triumph to His party. See explanation 2: 249; 3: 10-13 and 173.