BR 1057:4(1) :מזוג רתחין והא רתחין‏ : pour boiling water, and behold boiling water
See the entire entry for rṯaḥ, ra/eṯḥā n.m. hot object; anger

BR 1057:4(1) :מזוג רתחין‏ : pour boiling water
See the entire entry for rtḥyn n.m.pl. boiling water