The Missale Romanum of the Extraordinary Form states that the priest, deacon, and subdeacon, when holding their hands together, are to do so with the right thumb over the left so as to form a cross. The Ordinary Form just says the hands are to be joined. “Manibus Junctis” There has never been a prescribed way for the laity to fold their hands and particular ways of folding them are simply customary. The only postures for the congregation that are prescribed are the times to stand, sit, or kneel. The clergy have quite a few instructions to follow. Deacons, for example, are to keep their hands folded unless they have to perform a particular function. They are not to separate their hands when saying “The Lord be with you” before reading the Gospel, while saying, “Let us offer each other the Sign of Peace” or when dismissing the people – although doing so seems to be very common. This post also relates to the holding hands during the Our Father issue. If a person is free to fold hands, hold onto the pew in front, cross ones arms across his chest, etc, then why not hold hands? Requiring or even instructing the people to hold hands should not be done, however. One should always kneel at the proper times unless their is a legitimate reason for not doing so. This could be a personal, physical limitation or because Mass is being held in a muddy field. Since it is a prescribed posture, personal preference is not a sufficient reason to not kneel, stand, or sit. Having just had my knee replaced, I am well aware of the reasons for not kneeling. Small discomfort should not prevent someone from kneeling, however. I will say that being careful about how a person folds their hands can provide a way of focusing the heart and mind during prayer.