Overall meaning : The Almighty asserts that the desert Arabs are worse in their unbelief and hypocrisy than the urban unbelievers and hypocrites and that they rightly deserve to remain ignorant of the lawful and the unlawful and the laws that Allah has revealed to His Messenger, Muhammad, may Allah bless him and grant him peace. Allah is All-Knowing, All-Wise.
He also points out that some desert Arabs consider what they spend on good causes nothing but a loss, hence their reluctance to spend as they do not anticipate any divine reward whatsoever. They wait for some disaster to strike the Muslims and hope to see them run into serious trouble or be vanquished by their enemies. Ill fortune will only come their way. Allah is All-Hearing, All-Knowing.