What are the Sacred Months, and are rewards and sins multiplied therein?

The sacred months are: Dhul-Qa'dah, Dhul-Hijjah, Muharram, and Rajab "the month of Mudar which is between Jumada and Sha'ban." Some scholars are of the view that rewards and punishments are multiplied in them, based on His (the Almighty's) saying: (So do not wrong yourselves in them), and that sin in them is more severe and a greater transgression and burden than in other months, just as sins are multiplied in the Sacred Land. Al-Qurtubi mentioned that Allah multiplies the punishment for evil deeds and the reward for good deeds in them, just as He multiplies the punishment for the Prophet, peace and blessings be upon him, and his wives due to their elevated status.