Answered by Ustadha Shazia Ahmad
I read on Sunnipath that in the Hanafi school, baby vomit is najas (filth) only if it amounts to a mouthful, and that even a little of that does not invalidate the prayer. Is the same in the Shaf’i school?
Answer:
In the name of Allah, the most Compassionate, the most Merciful.
The short answer to your question is that the ruling for baby vomit in the Shafi’i school is not as easy as the Hanafi school.
The presence of vomit on one’s person during the prayer is not excused in our school, so one cannot pray with clothes that are affected by it.
The following link will also be useful:
Filth and prayer:
http://qa.sunnipath.com/issue_view.asp?HD=3&ID=2202&CATE=365
And Allah knows best.