BT BM 80a(33) :תיקלא כתיקלא וניפחא הוי תוספת‏ : weight is one thing (i.e., it does not include volume), while volume constitutes an addition
See the entire entry for npaḥ, nepḥā n.m. volume

BT BM 80a(33) :תיקלא כתיקלא וניפחא הוי תוספת‏ : weight is just weight while volume becomes additional
See the entire entry for tqel, teqlā n.m. shekel