This verse is to answer some questions about JAHAD, and the exceptions therein.

      Firstly it admits that fighting in the sacred month is prohibited and declared unlawful by Islam too. Fighting in these months is a great and heinous sin.

      Then it adds that this law too, like any other law may have its own exceptions - It should not be permitted that some evil doers, and mischief makers, under the name of the law, commit oppressions and corruptions. True that warfare is prohibited in certain months that are held sacred, but to bar people from God's way, and disbelief in HIM, and preventing people of having access to the House of God, and to expel its people from it, is more heinous a sin than fight in a sacred month.

Then the verse in its remarks alludes to tumult, counting it worse than slaughter; and that's true, because tumult is that sort of a crime that affects and injures the soul and the faith of man, where as slaughter impresses and harms the body. Therefore the Islam's instruction is to stand firm and steadfast in front of the enemy, in the sight of whom means can justify the end, and whenever, and wherever they raised their hands against you, you have every right to raise your hands to defend.