The Mishna on our daf discusses cases of a divorce that is dependent on fulfillment of a condition. If the husband says to his wife that he is divorcing her on the condition that she nurses his child, once she completes nursing the child the divorce will take effect. Two opinions are offered by the Mishna regarding the amount of time that is considered appropriate for nursing to be considered completed – the Tanna Kamma says that it is two years, while Rabbi Yehuda says that it is eighteen months. If the child dies during that time, the Mishna rules that she still fulfilled her obligation, and the divorce takes effect. This is true, however, only if the husband said “on the condition that you nurse my son,” implying that the nursing should go on as long as necessary. If he said specifically “on the condition that you nurse my son for two years,” the Tanna Kamma says that she must complete the two years, and if the child dies she has not fulfilled the condition. Rabban Shimon ben Gamliel disagrees and rules that also in this case the divorce would take effect, since she was not at fault.
Regarding the length of time that is considered normal for breastfeeding, we find wide variations in different cultures. In the Western world today, it is considered normal to nurse a newborn for six months to a year; a year and a half, or two years, would be quite a bit longer than what is ordinary in contemporary society. There were many different reasons for a lengthy period of breastfeeding in Talmudic times. First and foremost, was the difficulty in preparing or obtaining appropriate substitutes for mother’s milk. Even if the raw materials were available to make such food, it was likely beyond the financial means of many families.
Another reason for extended nursing may have been the fact that breastfeeding may act as a natural method of birth control, which allowed for spacing children. This was probably a more effective method in the times of the Mishna. Improved nutrition today limits the efficacy of nursing as a contraceptive.