The Su'ndi clergy study the movement and signs shown by the celestials - planets and stars - and use that knowledge combined with the information held in their vast libraries to determine the advice they give out during the ten-day ceremonies and when approached for advice on life.
The Su'ndi people trust the advice given out by the priests knowing that it is backed up by advice from the celestials to such an extent that they will cancel marriages and delay harvests on the priests say so. The priesthood are rarely, if ever, wrong on such matters and this has only backed up the power of the celestials in peoples minds.
Individuals will often seek out priests to get the celestials advice on matters both important and unimportant. The priests will offer a reading - in a similar way to ancient astrology - and the results will be used to provide advice.
