1- Is it permissible to wipe over socks during ablution, and what is the method for doing so? 2- What is the ruling on working in Islamic banks if the person in charge of investment engages in an unlawful transaction without the knowledge of others, and does this contaminate the rest of the money acquired through lawful means, and are the bank employees sinful for the money they have acquired? 3- Is the Hajj performed by individuals sponsored by Islamic institutions (such as Islamic banks) at their own expense 100% valid?

Working in usurious banks is prohibited, while it is permissible to work in Islamic banks if their transactions are sharia (definition)-compliant. As for nascent banks that strive to conform to sharia, it is permissible to work for them and encourage them. If an unintentional error occurs in a non-sharia-compliant transaction, it is obligatory to alert the person in charge, correct the transaction, and educate them. This does not affect the bank's sharia compliance unless the error is repeated. "And there is no blame upon you for that in which you have erred, but [blame is due for] what your hearts have intended. And ever is Allah Forgiving and Merciful."