The unmistakable sound of a WhatsApp message; my wife has been asked if she knows anyone who speaks Hebrew. It’s Neil Laidlaw, producer of the soon-to-open West End production of The Prince of Egypt. Neil’s a Scot, and very definitely not Jewish. There’s more Hebrew in the script and the lyrics of the show than the 1998 movie. Well, I speak Hebrew, and there is no way I’m passing this one on to anyone else.

In conversation with the show’s writer, Philip LaZebnik (Pocahontas, Mulan), I get the story of how Hebrew ended up in the original movie. “Stephen Spielberg wanted [the movie] to be definitive. He felt it would be the only version of the story many people would ever know. He wanted an authenticity and the Hebrew was a part of that.”

The original movie was, in LaZebnik’s words, “vetted,” by a team of some 400 theologians from differing faiths. But neither the movie, nor the musical, follows the biblical narrative slavishly. “Movies,” said Lazebnik, “have to be about relationships. And Divine relationships are just less suitable for the kind of storytelling we to do. We needed relationships between humans.”

Among the human relationships fleshed out in the musical is that between Tzipporah and her husband, Moses. The biblical moment in which Tzipporah saves the life of their sons by circumcising them with a piece of flint doesn’t make it to the West End stage (spoiler), but Tzipporah does get a backstory. “In dramatic terms,” Lazebnik records, “Tzipporah is all about freedom and that’s something she teaches Moses. The first time Moses gets an understanding of what freedom means, it’s when he is with her.”

Lazebnik, and the team, wanted the Midianites, from whom Tzipporah is descended, to have an authenticity and that, perhaps a little anachronistically for the more academically minded, meant that they too would, on occasion, slip into Hebrew. And that’s how Christine Allado, the Filipino-British star of Hamilton, needs to learn how to pronounce the Hebrew for, “I am free, I will be free, I will be forever free.”

In a scruffy rehearsal room in Islington, Allado and I went over the pronunciation of the Hebrew letter chet —what academics call a “voiceless uvular frictive”, or as less dauntingly, “think ch as in the Scottish word loch”. And we worked on the placement of emphasis — in Hebrew, most, but not all, words are accented on the last syllable. She’s going to be fine.

More problematic was the way cast and crew referred to the character of Moses’s mother: “Yok-eved”, with the emphasis on the “Yok”. Ofra Haza, the titan of Israeli music who voiced the character in the movie would not have been impressed. Fortunately, the Hungarian-born Mercedesz Csampai is never referred to by her character’s name during the show. And she clearly has had Haza on repeat. By the time I spent time with her, she had every intonation and inflection perfected.

Then there are the three young girls who, on alternate nights, will share the daunting task of a five-line Hebrew solo in the midst of the stand-out Oscar-winning song, When You Believe. Whoever suggested, “don’t work with children,” clearly didn’t foresee tiny mighty professionals like this. Together with the show’s music director, we worked on the gutteral ayin, the half-syllable sh’va and the confusion that arises in Exodus 15:11, where identical words are pronounced differently in successive phrases — first mi chamochah, then mi camochah.

There’s not a lot of Hebrew in the musical, but more than your average West End show. There’s enough to make this congregational rabbi excited, but not enough to give up the day-job.

Jeremy Gordon is Hebrew consultant to The Prince of Egypt musical and rabbi of New London Synagogue