Reference for Sanhedrin 102:17
א"ל וכי מפני שאתה דורש בת ובת נוציא זו לשריפה אם משמע להביא את הנשואה הביא את הפנויה ואם משמע להוציא את הפנויה הוציא את הנשואה
— [He holds that] the gezerahshawah serves the purpose to exclude an unmarried woman, whilst the superfluous'<i>waw</i>' serves to indicate the inclusion of a nesu'ah. And R. Ishmael? — Inraising the foregoing [objection] he thought that since R. Akiba had replied.'I interpret the superfluous waw', it proved that he had withdrawn his deductionfront the <i>gezerah shawah</i>.<span class="x" onmousemove="('comment',' For mere identity of phraseology is insufficient to deduce similarity of law. There must be a tradition from one's teacher, and supposedly handed down from scholar to scholar, going right back to Moses. (Pes. 66a: so Rashi's interpretation of the rule: No one may draw conclusions from identical phraseology on his own authority). Thus R. Ishmael thought that R. Akiba had abandoned this gezerah shawah, being doubtful of the authenticity of its tradition. ');"><sup>22</sup></span>