Many things in the Bible come in forties. The Flood took forty days and forty nights. Moses was on Mount Sinai for forty days. The people were in the wilderness for forty years. Other narratives also tell of forty years of one king of experience or another. This particular Shabbat when Moses begins to sum up his life's teaching we know that he will be reporting on forty years of leadership, but a question tugs at our minds. Forty years from Egypt to the Jordan River - when the journey really only needed eleven days? The traditional explanation is that eleven days would not have been long enough to turn the Israelites into a people, to build a sense of solidarity, to prepare for life in the Promised Land.

We of course have the benefit of centuries of subsequent history and human experience, and we know that things which happen fast are generally hard to handle. Imagine what would happen if we were all like the handful of child prodigies who are already finishing university degrees when they are barely into their teens. Adulthood would have come too fast. The struggle to grow up is never easy, but without the struggle we would not appreciate it. People who win the lottery and become instant millionaires are rarely able to cope with their good fortune; they are simply not ready. How long each stage in life should take is addressed at the end of the fifth chapter of Pir'kei Avot, a brave attempt at telling us what we should be doing at each milestone. It does not work in the same way for everyone, but the general principle is amply vindicated. Everything worthwhile takes time.

With this week's sidra we reach the end of the fourth Book of the Torah. It's exciting to complete a task, even the reading of a Biblical book. Joining in the declaration, "Chazzak chazzak v'nit-chazzek" - "Be strong, be strong, let us strength each other", is a moment of celebration. The first time you do it can never be forgotten - but how about the umpteenth time, when you have been a regular synagogue-goer all your life and you have been following the Torah reading for more years than you can remember? It is possible to say you're bored and it's all deja vu. But not if you are like one of my teachers whom I quote often. He used to follow the Torah reading each year through the eyes of a different commentator. This year might have been his Ibn Ezra year, last year it could have been Rashi and next year it might be Samson Raphael Hirsch. He reached old age and presumably never ran out of commentators.

I must admit that though I try to follow his method I do not always succeed, but I certainly find something new each year which I did not notice the year before. I call this the Ben Bag Bag way. At the end of chapter 5 of Pir'kei Avot, Ben Bag Bag (the word "Bag" may be an abbreviation for "Ben Ger", "the son of a proselyte") is quoted as saying, "Turn it (the Torah) and turn it again, for everything is in it; contemplate it, wax grey and old over it and do not stir from it, for you can have no better rule than this". Every time we encounter a given verse or teaching our circumstances have changed; we are different people and it is a different world. Every time we read a parashah we inevitably "turn it and turn it again", and it speaks to us with a new message.