Reference for Yevamot 69:7

אלא אמר אביי אשה מזנה מתהפכת שלא תתעבר ואידך חיישינן שמא לא נתהפכה יפה יפה:

in order to know the distinction between the seed that was sown in holiness and the seed that was sown in unholiness. It<span class="x" onmousemove="('comment',' Rabbah's explanation. ');">¹⁷</span> is also [intelligible In the case of] a captive and a slave; since on hearing from their masters<span class="x" onmousemove="('comment',' Of their impending liberation. ');">¹⁹</span> they exercise care.<span class="x" onmousemove="('comment',' Cf. supra notes 1 and 5. ');">²⁰</span> How is this<span class="x" onmousemove="('comment',' Rabbah's explanation. ');">¹⁷</span>

Jastrow