Slandering a Sahaabi by saying that he did not know anything about politics
Question

                What is the ruling on who says that the great companion Abdullah Ben ‘Umar, May Allah be pleased with them, does not know anything about politics. This sentence is insulting.
Praise be to Allah.
    ‘Abd-Allaah ibn ‘Umar (may Allaah be pleased with him) is a 
    great Sahaabi, one of the greatest scholars of the Muhaajireen (those who 
    migrated from Makkah to Madeenah). We should love him and all the Sahaabah, 
    and be pleased with them. It is not permissible to criticize them or any one 
    of them, because the Prophet  (peace and blessings of Allaah be upon 
    him) said: “Do not revile my companions, for by the One in Whose hand is my 
    soul, if one of you were to spend the equivalent of Uhud in gold, it would 
    not amount to a mudd of one of them, or half of that.” 

    And Allaah is the Source of strength. May Allaah send 
    blessings and peace upon of our Prophet Muhammad and his family and 
    companions. End quote.