The 11th month of the Jewish year began this week. The month of Av is mainly known for the intense period of mourning that marks its beginning and culminates in the saddest day on the Jewish calendar, Tisha Be’av.The destruction of both the First and Second Temples, the crushing of the Bar Kochba rebellion by the Romans, the later tragedies of the expulsion of the Jews from Spain and the innumerable pains and killings of Jews in the wars of the 20th century are all somehow commemorated and associated with this month.Yet the month contains rays of hope and optimism for us as well. The 15th of Av is a minor holiday marking positive and joyous ritual and social events that formed Jewish life in earlier times. The mourning over Jerusalem’s destruction is always tempered even on Tisha Be’av itself by the realization, certainly partly achieved in our time, of its rebirth and rebuilding. The month therefore comes to symbolize the eternal resilience of the Jewish people. The month bears an addition to its name. It is called menahem Av, a month that will bring solace and comfort to long-suffering Israel. There is no negative attribution given to the month even though it is obviously the least fortuitous month of the year for the Jewish people. There is therefore an ambivalence of attitude and approach to this month. We dread its coming and yet welcome its passage and the message of hope and solace that it nevertheless brings with it.The Talmud teaches us that the current names of the months of the Jewish calendar year are Babylonian in origin, brought into Jewish society by the return of Ezra at the beginning of the Second Commonwealth. Yet the name of the month of Av has a distinctly Hebrew ring to it. Av in Hebrew means father, head or leader. It also intimates strength and greatness. The Talmud teaches us that it also implies that there are toldot – descendants, consequences if you will – that inescapably derive from the presence of an av.As such it appears that this month is most aptly named and called. For the events commemorated in it have had a major effect upon Jewish and world history. And the descendants of Av continue to influence our national and personal existence.The Talmud again reminds us that the absence of the Temples and Jewish control over the Land of Israel, the state of rootlessness and alienation that exile foisted upon the Jewish people for many centuries, have even changed the physical and emotional environment of our world society. The tastes of foods, the aroma of flowers, the laughter of humans were all changed and somehow diminished by the destruction of the Temples and the exile of the Jewish people. In these respects as well as in many others, Av became and remains the most consequential month of the Jewish calendar year. It is the month that casts the longest shadow of all over Jewish life and history.The rabbis taught us that those who are able to truly feel the loss of the Temples and Jerusalem within their hearts, whose mourning is heartfelt and genuine and not merely externally expressed and pro forma, are privileged to see the other side of the month of Av in its consoling comfort and promise of redemption and better times. This ambivalence of feeling, a deep sense of loss combined with a sense of soaring optimism that is able to overlook current difficulties and misfortunes, makes this month of Av truly special.The ninth of Av marks our sorrow and pain while the 15th of Av lifts our spirits and points to success in family and community matters. The fact that these dates are close to one another prevents us from having a permanent feeling of depression and sadness and burdening the entire month with a black shroud of negative feeling. The addition of the word menahem – one who comforts and consoles - to the name of the month is meant to bring this lesson home to us.It is necessary to maintain this upbeat spirit for Av leads to the month of Elul and with it the anticipation of the new and good year awaiting us. Av and all of its days will yet be a source of happiness and permanent achievement for all of Israel.The writer is a noted scholar, historian, speaker and educator.