The scraping of the bark of the u'a, one must quickly scrape off the bark from the outer side/back." "Saeina" refers to the scraping or removing action, "pa'u" refers to the bark, "pitu" means back or outer side, and "tua" also can refer to the back or behind. The context suggests that during the siapo-making process, it's essential to quickly remove the outer layer of the bark to access the inner layer, which is used to make the cloth.