Reference for Shevuot 35:1
ואי בעם הארץ אידי ואידי אכל שני זיתי חלב בהעלם אחד הוא
And if an illiterate man,<span class="x" onmousemove="('comment',' Who acted unwittingly in both cases.');"><sup>1</sup></span> then both acts are the same as eating two portions of forbidden fat, each the size of an olive, in one spell of unawareness.<span class="x" onmousemove="('comment',' For which he brings only one sin offering. Here also, since he is illiterate, he is not aware, when she tells him she has become unclean, that he has committed a sin by cohabiting near the time of her period; or that it is prohibited to withdraw immediately. Since he has no knowledge of guilt between the two acts (entering and withdrawing) , he should bring only one sin offering.');"><sup>2</sup></span> Well then, [shall we say,] it was not near the time of her period?