It´s Palm Sunday, and as the Spanish say:
Domingo de Ramos, quien no estrena algo, se le caen las manos
(“On Palm Sunday, the hands drop off of those who fail to wear something new”)
Several people have said this to me today, and a few minutes searching on the net seems to bring me to the conclusion that nobody knows why you have to wear something new, you just do. It´s probably a folk saying to remind people that they should splash out a little before the processions in order to honour the Church – the traditional “something new” is usually a pair of white socks to wear during the marching, and in some parts of the country these are given by grandparents as gifts to the sprogs.
Another charming tradition is the following:
During the cuaresma you are supposed to tie a knot into a homemade rope (the soga) every time you pray at the Church. Then, on Palm Sunday, you bury this rope somewhere special to you and it brings you good luck until the next year (the milagro). It´s called the “soga de los milagros”. Especially big in Jaen and Cordoba, this one. The homemade soga is also used as a belt on penitent robes during some of the processions (as well as flagellation, if you´re into that). Often made out of esparto.