Reference for Niddah 53:9

אמר רב אחא בריה דרב עוירא א"ר יצחק

[The law, however, that it] is to be attributed [to the existing embryo] applies only<span class="x" onmousemove="('comment',' Lit., 'and they only said'. ');">⁸</span>

Jastrow

Jastrow