When Aharon Rubin was young, his family went on a picnic to Kew Gardens. "I saw a man sitting perfectly still on the grass, who my father told us was 'meditating'," he recalled. "I think that must have been my first real encounter with the expression."
The Manchester-based scribe and school-teacher, who is in his early 40s, has just published his own practical guide to Jewish meditation, Eye to the Infinite. Meditation is commonly associated with the alternative Jewish scene, stemming from the chavurah groups of '60s America and more latterly the Jewish Renewal movement.
But what makes Rabbi Rubin unusual is that he comes from an impeccably Charedi milieu. His book, while aimed at general readers, carries copious footnotes, citing the Talmud, Zohar and other rabbinic works, which show the depth of his learning.
Meditation has long a pedigree in Judaism, he explained. "We were the original meditators. Almost definitely the earliest recorded account of meditating is of Isaac who the Torah says 'went out to meditate in the field.'"
He grew up praying in some of the frummer synagogues in Golders Green. His late father was "always into Kabbalah" and had a PhD in Jewish mysticism. At the age of 12 or 13, he himself was reading the works of Aryeh Kaplan, the first Orthodox rabbi to popularise Jewish meditation.
Going on to study at Gateshead and then Mir Yeshivah in Israel, he pursued his mystical interests more deeply, though unobtrusively. "I had access to the seforim of Ari Hakodesh [the 16th-century kabbalistic master, Rabbi Isaac Luria], although I kept them quiet," he said. "I used to get up early and go to a little room, my little shtibl with my books, next to my bedroom, which I could lock.
"My father didn't like me to learn Kabbalah at a young age. Although he discussed this sort of thing, he didn't think I would take up the sefer [book] and start learning."
He wrote the book because he was disturbed that people were often unaware that "there is so much material in our literature that points to meditation ‑- I just touched the tip of the iceberg".
While some books on meditation are about general wellbeing, his has a clear spiritual objective: to help people feel closer to the divine presence - the "inner flame which is so easily accessible".
His knowledge is distilled into a clear prose that explains the key concepts of Kabbalah; the meditation exercises he offers are taken from classic Jewish sources, using visualisations based on the spiritual significance of the Hebrew alphabet or the religious symbolism of colours. Techelet, the original dark blue of the tzitzit, recalls the sea - "the calm, deep blue colour stilling the mind" - but is also linked to Kisei Hakavod, the Divine Throne of Glory.
"I use quite a bit of visualisation because in today's world, we are bombarded by images that disturb the clarity of the brain. A person needs to be able to escape from that and have their own set of images."
But you should not overdo it. "Somebody came to me the other day and said he falls asleep during meditation. That's clearly a sign they are meditating too much. You've got to go little-by-little. Five minutes is not too little, two minutes is not too little - you've got to work on that."
The meditation below, for example, is a spiritual workout you can do for five, 10 or 15 minutes.
And you are not too young to learn. Sometimes when he leads davening with seven-to-eight-year-olds at school, "I often tell them just to close their eyes and imagine God is around them, around the street, around the world, to draw the circle bigger and bigger. You should see them, they are so ready for it, it's beautiful."