Is it permissible to raise one's hands when supplicating with the Kaffarat al-Majlis (expiation for the sitting) and what is the evidence for this?

It is sunnah for a gathering to conclude with the supplication for expiation of the gathering: "Glorified are You, O Allah, and praised be You. I bear witness that there is none worthy of worship but You. I seek Your forgiveness and repent to You." It is not legislated to raise the hands when uttering this supplication because it was not reported from the Prophet (peace be upon him) nor from his companions that they did so.