Q. Why do Jews wish each other “To 120!”?
A. The greeting is based on the final chapter of D’varim, which records that Moses lived to 120 in good mental and physical shape. The implication is not merely that we wish a person to have a long life but we hope they will retain their faculties to the end.
Once upon a time the whole idea of living to 120 was unthinkable (we can discount the notion of reaching 900 or so which is recorded of our early Biblical ancestors). Life expectancy was much lower, and sometimes it was a real achievement – certainly a real blessing – to reach 50 or 60. In those days the old age homes (now called by more felicitous names) accepted people from the age of 60, where now residents rarely apply for admission until they are 80 or over.
There is still a problem about the quality of life enjoyed (or endured) by old people. Some have mental clarity and a declining body: others have the opposite. The ideal is a body that remains in good condition to the end and a mind that remains sharp.
Moses was fortunate in that “his eye was not dim nor his natural force abated” (Deut. 34:7). How then can the Torah report (Deut. 31:2) that Moses complained, “I am no longer able to go out and come in”, i.e. “I am unable to be as active as before”? One of the rabbinic explanations hinges on the words, “I am no longer able…” It comments, “He would have been able to go out and come in as before but God would not allow it”. In other words, God told him that his life span was concluded and his career had to cease.
These days there are facetious modifications of the traditional wish, such as “May you live to 120 and six months”. Why the extra six months? “You wouldn’t want to die suddenly, would you?” Another version is, “May you live to 125”. Why the extra five years? “To allow for inflation!”