Numbers Rabbah 6:7–8
"Record them from the age of thirty years up to the age of fifty" (Numbers 4:23). From here it has been inferred that "at age 30 a man attains his full strength" (Avot 5:25) . . . In the tent of meeting they were disqualified from the age of 50 and onwards, but when they entered the Land of Israel they were only disqualified by reason of their voice.
I have always been curious about Pirkei Avot's laying out of particular life-stage milestones according to age. What are the different stages of life about? What is "supposed" to happen to us when? What can we expect as we grow up and (God willing) grow old? Is there a point at which we are "disqualified," turned away as less useful than before for service to our community?
The question is with me as—in my own midlife crisis, somewhere between the ages of 30 and 50—I remark with sadness about the way our society emphasizes the hope and promise of youth over the wisdom and richness of experience.
The teaching of Pirkei Avot, in the name of Rabbi Yehudah ben Tema, lists life stages by educational curriculum and then by decade, ranging from the beginning of one's education at 5 to the age of 100. To what extent are these ages and their associations relevant to us today? I like the midlife ones—strength, understanding, the idea that the ability to give good advice comes only after a few decades of living (Rabbi Yehudah ben Tema suggests age 50). I like that there is the idea of a "ripe old age" and a strength in one's later years (age 80 is a second age of strength). I wonder to what extent the advances in medicine and longevity make Rabbi Yehudah ben Tema's ideas of 90 ("stooped over") and 100 ("as if he were dead") obsolete, and to what extent the increase in Alzheimer's and other memory-loss disorders might affect his generalizations.
As the midrash in Numbers Rabbah suggests, age sometimes matters—and sometimes does not. Traveling through the wilderness, the work of carrying burdens might become too difficult for aging bodies, and so "from the age of 50 onwards" individuals were considered too old for such tasks. However, once in the Land, where the Tabernacle had a more or less permanent abode, the service of the Levites consisted chiefly in singing Temple hymns. The need to protect one's physical body from harm was no longer a consideration; as long as one was able to sing, one continued in the divine service.
The questions for our generation, in which we live longer lives and in fuller health than any prior, are about meaning and balance. What is age discrimination, and what is appropriate recognition that one's strength is waning? Who determines one's passing from one life stage to the next? And how can we, as a society, be sure to respect the wisdom and strength of those who have lived the longest, and recognize each person's individual strength and voice at any age?