It is narrated from Muqatil bin Sulayman (may Allah have mercy on him) that Allah Almighty said: O company of the wives of the Prophet (peace and blessings be upon him)! You see the revelation, and you are more deserving of piety than other people. And before that He said: "O wives of the Prophet, whoever of you commits a manifest indecency" [Surah al-Ahzab: 30]. Muqatil said: By indecency is meant disobedience to the Prophet (peace and blessings be upon him). Then, mentioning the rest of the verse, he said: the doubled punishment refers to the Hereafter, and "that is easy for Allah" means that punishing her is easy for Allah. And whoever obeys Allah and His Messenger and does righteous deeds, We will give her reward twice, that is, in the Hereafter, for every prayer, fast, charity, takbir and tasbih, in short for every good deed, We will give a reward equal to twenty good deeds. And We have prepared for her a noble provision, that is, good provision in Paradise.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب النكاح / 13428