Overall meaning : Allah Almighty says to His Prophet, may Allah bless him and grant him peace: Say, Muhammad, ‘Do as you will, for Allah will surely see all your deeds and will repay you according to them; and so will His Messenger, may Allah bless him and grant him peace, and the believers see what Allah will reveal to them regarding these actions and will thus testify as to what you have done. Then, on the Day of Judgement, you will be brought before Allah who knows the unknown and the manifest, and He will declare to you what you have done and repay you accordingly.’
The Almighty then indicates that among those who did not take part in the Battle of Tabuk and stayed behind are left awaiting Allah’s command as to whether He will punish them or pardon them. Allah is All-Knowing, All-Wise.