Halakhah for Chullin 191:20
אכל מזה כזית ומזה כזית סופג שמונים
R'Shesheth said: That part which Bar Piuli had removed, is according to R'Judah forbidden by the Torah.
Sefer HaChinukh
And [it] is practiced in every places and at all times by males and by females. And one who transgresses it and eats a [whole sciatic nerve], even if it is less than an olive's-worth - or eats a kazayit (the size of a large olive) from a large sciatic nerve - is lashed (see Chullin 96a).
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