Yosef Karo, Translation:Shulchan Aruch — Orach Chaim 456…
“ Paragraph 3 - Even though we do not measure out flour on a holiday in order to knead, on the festive days of Passover when we do not make dough larger than an issaron, it is permitted to measure. There are those who forbid this and say to estimate roughly but not to take more than an issaron (and such is the practice) . ”
