Each of the Jewish festivals coming up in the next month has special religious obligations attached to it. They are like forfeits in a game of pass the parcel – a set of sometimes outlandish and seemingly unconnected actions we must perform.

We begin on both days of New Year with a requirement to hear a hundred notes blown on a shofar, a musical instrument of Biblical origins. Most people listen to the notes in synagogue.

After New Year, we prepare for Yom Kippur - in English, the Day of Atonement. This day’s practices include fasting and shunning all physical pleasures.

When we get home from synagogue at the end of Yom Kippur, before breaking the fast, we must begin building an outdoor hut where, according to the Jewish scriptures, we should spend mealtimes during the next festival – the seven-day Succot or Tabernacles which begins this year on October 13th.

Another obligation of Succot is to hold four species – the lemon-like Citrus Leviticus, and branches of palm, willow and myrtle – each day and recite a blessing. The observance of this law in Jesus’ day may explain why branches were laid before him in the New Testament account that inspired Palm Sunday.

Straight after Succot come another two festival days. On the second of these, the synagogue is transformed in to a dance floor where wild celebrations take place to mark the completion of the annual cycle of reading the Pentateuch, the five books of Moses.

The practices themselves are quirky enough, but this year we face a particularly odd challenge in performing one of them. Synagogues are on high-alert to stop any fake shofars from being used.

A shofar is an animal’s horn hollowed out in accordance with Jewish law. It only passes as a shofar if it is perfect and free of cracks. But Israel’s Judaica market – the source of most shofars even for use in the Diaspora – has been flooded with cracked horns that are sealed up with glue and passed off as kosher shofars.

The Israeli rabbinical authority responsible for approving religious artefacts has called for all communities to check their shofar came with a sticker confirming it is kosher. The reason for the concern is that is that in the eyes of Jewish law, hearing the notes blown on anything but a kosher shofar is a waste of time - congregants have not met their obligation.

Nathan Jeffay is an Orthodox Jew and writer on Jewish affairs