א"ל ר' ירמיה לר' זירא וקים להו לרבנן בין שליש לפחות משליש א"ל לאו אמינא לך לא תפיק נפשך לבר מהלכתא כל מדות חכמים כן הוא
§ Rabbi Yirmeya said to Rabbi Zeira: And are the Sages able to discern precisely between produce that reached one-third of its growth and produce that reached less than one-third of its growth? Rabbi Zeira said to him: Do I not always tell you that you must not take yourself out of the bounds of the halakha? All the measures of the Sages are like this; they are precise and exact.