Mira Epstein, 8, of Bethesda, lightly touches the end of the feathered pen that her grandfather, Richard Epstein, uses to finish the last details of the torah at Chabad of Potomac on May 18, 2014 in Potomac, Md. (Katherine Frey/The Washington Post)

To write a Torah, a scribe must pen 304,805 Hebrew letters using a feather quill on sheepskin parchment — without making a single mistake. Forget auto-correct. Even one error would invalidate the whole text, making it unfit for use in a Jewish house of worship, according to custom. So completing a Torah is a cause for celebration. Completing one as an amateur is almost unheard of.

Richard Epstein, 74, a psychiatrist and a member of Chabad of Potomac, did just that on Sunday. He inked in the final letters of the scroll that took him eight years to write, an accomplishment that was marked by singing, dancing, and wonderment at the synagogue.

“I feel like basically the Torah wrote me, more than I wrote the Torah — that it really shaped me,” Epstein said. “When you write, you go so much slower than you think, and especially when you’re writing the Torah. It’s wet and it’s gooey.”

That painstaking process helped him appreciate the biblical precepts in a way he never had before, he said. Following a Jewish tradition, he spoke each word and then each letter in that word aloud before he wrote it. He found that he was thinking more deeply about the familiar stories and even dreaming about the passages he had penned that day.

He became interested in writing a Torah — the scroll containing the five books of Moses that is read in synagogues — nearly a decade ago. He met with professional scribes who taught him the craft. Almost all Torah scrolls are written by a scribe, called a sofer, who starts training as a young adult. For a professional sofer, a Torah takes 11 to 12 months. Most work in Brooklyn or in Israel.

Richard Epstein spent the past eight years writing a Torah by hand, a very painstaking process in which even one misshapen letter can invalidate the whole text. (Katherine Frey/The Washington Post)

“It is absolutely unique for someone at his age with his background to train himself to be a sofer. I don’t think it’s ever been duplicated,” said Rabbi Shmuel Kaplan, the regional director of Chabad.

Epstein wrote smaller texts first, including a scroll of the Book of Esther and the text for the inside of a mezuzah, the marker that Jews put on their doors, before beginning the Torah.

“I felt I wanted to be closer to God, and I felt, ‘What better way to be closer to God than the gift that he made to the Jewish people?’ ” Epstein said.

Mendel Bluming, rabbi at Chabad of Potomac, said congregants eagerly tracked Epstein’s progress as he worked on text that is central to Jewish worship and identity. “The Torah is not just rules to do within your life. It really is the DNA that makes our people exist,” Bluming said. “One thing that really inspired me is how involved the community became.”

Bluming said that the specially prepared parchment and other materials for the Torah, which the synagogue purchased, cost about $10,000. To fund the project, congregants paid to sponsor pieces of the text, from a single letter to an entire portion that makes up one week’s reading in synagogue.

Those donors had the opportunity Sunday to participate in the writing of the Torah. Wearing a magnifying glass strapped over his yarmulke, Epstein inked in the final letters. A member of the community recited each letter with him and held the end of his quill. The congregation danced the finished Torah on a parade through the streets of Potomac.

Lisa Rosen wrote a letter alongside her son Jonah, 20. Seven years ago, when Jonah was preparing for his bar mitzvah, the family sponsored Epstein’s writing of Jonah’s bar mitzvah portion, and Jonah watched Epstein work on it. “It was a very important part of his appreciating becoming part of the community,” Rosen said.

Richard Epstein puts the finishing touches on the Torah at Chabad of Potomac on May 18, 2014 in Potomac, Md. (Katherine Frey/The Washington Post)

Fran Hisler donated to the project in memory of relatives who were killed in the Holocaust. She said she sponsored a verse in Deuteronomy that refers to God avenging wrongs against the Jewish people. “This is a celebration that we’ve made it, despite all attempts to murder our people and inhibit us,” Hisler said. “To me, that’s the ultimate healing.”

Young children created Torah artwork using sand and glue, and held balloons with the outline of a Torah. Teenagers lined up for their chance to ink in a letter. “The Torah is our life, you know?” said Yankel Katzman, 18.

For Gerdy Trachtman, it was a moment to remember her husband. After he died, she sponsored seven letters in the Torah, which spell out his Hebrew name.

“It’s not an object that has died. It renews itself all the time,” she said after she wrote her letter with Epstein. “On the one hand, it is the oldest tradition we have, never changing. On the other, it is the newest, renewed.”