Reference for Chullin 141:34

טומאה חמורה לגר וטומאה קלה עד לכלב משום דלא חזיא לגר הוא

[it is nebelah] until it becomes unfit for a dog.<span class="x" onmousemove="('comment',' And as the undigested food if vomited out would be fit for a dog it should, according to R. Johanan, render the eater unclean immediately after sunset, nevertheless the Divine Law declares him clean obviously because unclean matter that has been swallowed cannot render unclean.');">²²</span>

Jastrow

Jastrow