Why didn't Prophet, sallallaahu ‘alayhi wa sallam, punish ‘Abdullaah ibn Ubayy when it was known that he was involved in the slander incident about ‘Aa’ishah, may Allaah be pleased with her, though others involved were punished?

All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad, sallallaahu ‘alayhi wa sallam, is His slave and Messenger.

First of all, it should be mentioned that there is a difference of opinion among the scholars whether or not the Prophet imposed the Hadd (the corporal punishment determined by the Islamic Law) on 'Abdullaah Ibn Ubayy. Some of them are of the view that the Prophet applied the Hadd on him. This opinion is considered by Ibn Hajar to be the strongest one, as he stated in response to those who considered this view to be weak, "The opinion which is considered weak is indeed the authoritative and an authentic opinion.'' Ibn Hajar stated beforehand, "It is reported that he was mentioned among those on whom the Hadd was applied, this is reported by Al-Haakim and it is a reply to the statement of Al-Maawardi who considered the view that the Prophet did not punish him, to be authentic."

However, some other scholars are of the view that the Hadd was not applied on him giving the evidence of the narration by 'Aa'ishah "When the verse about my innocence was revealed, the Prophet stood on the pulpit and recited the verse in this regard, and when he descended from the pulpit, he ordered two men and a woman to be lashed." [Ahmad, At-Tirmithi and Ibn Maajah] (These two men were Mistah ibn Uthaathah and Hassaan ibn Thaabit, and the woman was Hamnah bint Jahsh, as reported in a narration by Abu Daawood ).

The scholars who adopt this opinion sought the wisdom in this, and said that the Prophet did not impose the Hadd on the hypocrites, as the purpose of Hadd is to purify the person from sin and the hypocrites do not deserve that, so it is as if the Prophet, sallallaahu ‘alayhi wa sallam, left their matter to the Hereafter.

Allaah Knows best.