What does 'Suaimhneas siorrai da hAnam dilis' mean?

'Suaimhneas siorrai da hAnam dilis' is an Irish phrase that translates to 'Eternal peace to his faithful soul' in English. It is often used as a tribute or a prayer for the deceased, wishing them everlasting peace in the afterlife. This expression reflects a deep sense of respect and mourning for those who have passed away.