Several years ago, at a seder, I was introduced to a new custom.

When it came time to sing Dayyenu, a Persian-Jewish friend passed us all a spring onion each.

“In my family,” she said, “we hit each other over the heads with spring onions while we are singing this song.”

“It’s supposed to get out of our heads any feeling that we might want to remain in Egypt. So we remind each other by hitting our heads that we do not want to go back there.”

I instantly fell in love with it, and have adopted it into my own family seders. In fact, in my home, it can turn into a bit of a food fight, as we chuck the spring onions around the room.

One year, a Muslim friend came, and was quite baffled by the proceedings. I put quite a unique twist on my seders, and try to make them fun. That year, I had people dress up as the Ten Plagues from bits of fabric around the house, and do a lip-synching competition to the Prince of Egypt soundtrack. As he left, he said: “I can believe all of it is normal Judaism, apart from that bit with the spring onions.” I said: “That’s the only bit that was a real tradition!”

Maybe you might not bash your dinner guests with greenery, but you do sing Dayyenu, don’t you? It’s such a highlight.

I worry that some of our families’ seders don’t get there. The food’s coming out of the oven, everything has already gone on far too long, you’re anxious to eat, maybe you skip this important bit. I hope you don’t.

How about afterwards, when you’ve finished eating: who does the whole thing? Who carries on and sings hallel afterwards, and does the benching, and drinks the next two glasses of wine?

I hope you do. In fact, if this sermon has a message, it’s this: do the whole seder.

As you will see, this is not just me being a stickler for making sure people treat liturgy seriously, or insisting on the importance of halachah. This is about how we live our lives.

Our story begins with slavery and ends with freedom.

So, when you come to have your Pesach meals, make sure you don’t just tell the story of slavery. Make sure you talk a good deal about the freedom that comes afterwards.

The haggadah is actually split into two parts. In the first half, we are supposed to see ourselves as slaves in Egypt, weighed down by the yoke of bondage. Then, we eat. After dinner, we are free. We cross the Sea of Reeds and sing praises to our God. We raise a glass of wine to our redemption. We raise another glass to our future. We keep back a fifth glass for Elijah, who will come and bring about the final redemption, when everyone everywhere will finally know freedom.

Now, which of those two halves of the meal is more important?

Of course, it’s the second one. We don’t get together with our families and communities to dwell on how miserable it was to be stuck in Egypt. We get together to rejoice that we are free. How wonderful is this festival, the season of our liberation, that reminds us of that miraculous exodus out of oppression.

We sing Dayyenu (and bash each other with spring onions) immediately before we eat. That moment comes on the cusp between staying in slavery and leaving for liberty.

Dayyenu comes at the point where we are leaving slavery for freedom. By bashing each other’s heads with the spring onions, we say: “don’t leave any part of your head there! Don’t go back there, not even in your mind! Don’t dwell on those narrow places that kept you oppressed!”

Come on, we’re about to be free. We’re about to eat. Let’s look now to the future, where we will never have to think about those things again.

There’s a good reason why we might use spring onions in particular for the hitting. When the Israelites do get free, and start wandering in the desert, they start moaning about how much they miss slavery. They whinge about how much better being oppressed was. And what do they say they missed eating? The onions.

Those Israelites understood something. Being oppressed can feel easier than getting free. Sure, Egypt might have involved great persecution, but you always knew where you stood. Getting free, or at least trying, is tough. It’s unpredictable. It combines dizzying excitement with a terror of the unknown.

So we have to remind ourselves, over and over again, that however difficult freedom feels, it is better than oppression. However easy it might be to wallow in misery or stay in a victim mentality, there is so much more to be gained from shaking off our chains.

The first part of the seder says: we were slaves in Egypt. The second reminds us: but God helped us get free.

In the 19th Century, the Progressive Jew Israel Abrahams wrote about exactly this optimism for the Jewish Chronicle. He began his article by saying how wonderful it was that even persecuted medieval Jews insisted on keeping their doors open for Elijah on seder night, adamant that God would protect them. He said: “truly there is no danger to Judaism while such eternal hope prevails over despair.”

Israel Abrahams goes on to talk about the messianic hope that Jews hold at Pesach. Look at the bigger picture of history, he says, and you can see that it is not a delusion. “Persecutions come and go, but the Jews go on.” Away with all pessimism,” he says, “away with all pessimism.”

Can you believe that such words appeared in the Jewish Chronicle? How much can change in just over a century! Today, there is no way our communal organs would say how great it is that Jews would keep their doors open. They’d tell us to keep them locked. They’d sell us a more advanced security system. They’d put in a fundraising pitch for CST while they were at it.

Can you imagine any of our great and noble communal representatives sharing a positive view of Jewish history and an even more positive view of our future? No, their message is always the same: we are terrified; we have always been persecuted; we always will be persecuted. All we can do is build up bigger defences, hire tougher security guards, buy more effective security cameras; and keep our bags packed to run away just in case.

Sometimes I think Anglo-Jewry is stuck in the first half of the seder. It is as if many of us believe that we ourselves were slaves in Egypt, but nobody can believe that we were redeemed.

Do any of us really believe we are worse off than Jews were in the time of Israel Abrahams? Do we have more reason to cower than did medieval Jews? And, if we did, is cowering behind even greater security really our best answer?

The point of the seder isn’t that we were slaves. It’s that we got free.

Think of the wonderful things Jews are doing, and that British Jews have done. We are stars of stage and screen, fully represented at every level of politics, working in every strata of society, innovating, building, and living happy lives among our neighbours.

Sure, you can talk about the bad bits. Whenever I talk about the good, someone is eager to remind me of some proof of how much they all hate us. Some people leap to lecture on antisemitism and misery at even the suggestion that things might sometimes be good. That is a mentality that keeps your head in Egypt.

It’s not that everything is miserable and it’s not that everything is fine. It’s always a bit of both, no matter who you are.

The point is that everything could be wonderful. We could build a future so much better than this one.

Many times, with God’s help, we have achieved wonderful things.

When you take up the third cup at your seders, remember all the incredible things you and your ancestors have achieved.

When you take up the final cup, look towards the great utopia you can build here on earth.

And when you leave your Pesach seders this year, don’t carry around with you the slavery and misery of the first part of the meal. Bring out into the world Judaism’s message of hope.

Keep your eyes always on the best of what may be to come.

Beat out of your head any desire to wallow in misery.

Do not leave any part of yourself in Egypt.

Shabbat shalom.