The Battle of Uhud was a lesson for the Muslims. They learnt a lot from it.
They learnt how to obey the Prophet [s] at any rate, for obedience to him meant victory, and disobedience meant defeat.
Our Master Muhammad [s] was badly wounded. The reason was that he ordered the bow men not to leave their place on al-Ainain Mount at any rate, but they forgot his order.
The Arab tribes scorned the Muslims' shaken reputation. Meanwhile, the hypocrites and the Jews rejoiced at their misfortune.
For this reason, our Master Muhammad [s] wanted to restore Islam to its reputation. So, he reorganized his troops to chase the polytheists.
source : sibtayn