It was an atypically hot May afternoon in Marin County, with temperatures reaching the mid-80s, but 3-year-old Menachem Mendel Scop of Mill Valley stood out in the sweltering sun as a portrait of composure.

Positioned calmly on top of a family chair, Mendel (as his relatives call him), casually planted himself upright while various members of his family and community each took a turn delicately cutting off pieces of his hair, trimming down his lengthy locks with each shear.

Unlike how he usually spends his weekends, on this Sunday Mendel was participating in his upsherin, a traditional rite of passage where a Jewish boy celebrates his third birthday with his first haircut.

The celebration occurred at Mendel’s family home, which also serves as home to Chabad of Mill Valley, run by Mendel’s parents, Rabbi Hillel Scop and his wife, Chana.

“We think of a young child as a tree,” said the rabbi, a native of Johannesburg, South Africa, who has lived in Marin for nine years.

“You don’t want to cut the tree down while is it still growing, because then it would not be able to blossom and produce fruit. When Mendel gets his hair cut he will begin the process of blossoming and becoming a man, because now he will be able to put on his yarmulke, as well as learn about the tradition of the tzitzit.”

The upsherin marks the beginning of a Jewish boy’s growth from being a baby without any responsibilities into a developing youngster who can begin taking an active interest in his religious education.

Although Mendel remained quiet during the ceremony — not surprising for a 3-year-old on display in front of a large gathering of people — his family was confident that he knew about the circumstances of his big day.

“He’s a little shy right now,” said his father. “But he’s very much aware of the situation and we know he is very excited about the celebration.”

Mendel’s mane, which took almost 20 minutes to trim, was donated to the charity foundation Locks of Love, which provides hair to children afflicted with cancer and undergoing chemotherapy.

“Along with making this passage, he is also committing a good deed,” said Scop. “He had the opportunity to perform his first mitzvah.”

Mendel’s birthday was actually April 10, which fell this year during the Omer, during which haircuts are forbidden. So the family had postpone the celebration until May 6, which coincided with the Jewish holiday Lag Ba’Omer, a celebration that would allow the upsherin to occur.

Lag Ba’omer is the 33rd day of Omer, and is a historically festive Jewish occasion marking the end of a plague that afflicted 24,000 of an ancient rabbi’s students, as described in the Talmud. Along with praising the merits of Mendel’s upsherin, Scop also went into detail about the importance of Lag Ba’Omer, an effort he made in order to better inform the Marin County crowd of the traditions of the Jewish faith.

When he moved to the North Bay nearly a decade ago, Scop felt that there was very little Jewish community activity in the area, something he has sought to improve by starting the Chabad center in his home, as well as opening a preschool, which began operating in January.

“We want to create more awareness in the area of the wonderful Jewish traditions,” he said. “We want to share this wonderful heritage with others, regardless of the environment, whether it’s religious or secular.”

Though the Sunday celebrations represented another case of Scop opening up the traditional rites of Judaism with his community, the day truly belonged to Mendel, who, before getting his very first haircut, received some wise brotherly advice from his older sibling Schneur.

“I told him not to cry when he is getting his haircut,” said the 8-year-old Schneur, who had his own upsherin five years ago.

“And I said that he’ll need to use more sunscreen on his head.”