Q: The rubrics gave no indication of the numbers for foot washing hence it could be more than twelve people. But this will prolong the rite if there are more than twelve like fourteen or twenty-four. In such a situation can the concelebrant assist?
A: You are correct that the rubrics do not say how many people may have their feet washed. It may be 12, fewer, or more. The rubrics are silent about a concelebrant helping, but I see no reason why he couldn’t.