I searched for my son’s face in the rear-view mirror. He was huddled in the shadows of the back seat.“So when you get there, Jewish custom mandates that you say nothing to the bereaved until she first addresses you,” I advised him, conscious that he was dreading the moment we would reach our destination.Yuval, 11, stared out into the dark of night. He nodded his head ever so slightly, dropped his shoulders, and sighed.My son was on his way to pay his first shiva visit, a condolence call to a mourner during the weeklong period after the passing of a family member that is customary in Judaism. Paying a shiva call, as it is known, is a big mitzvah, a positive commandment that honors both the deceased and the living. In this instance, my son was more connected to the mourner than I was. His homeroom teacher, Iska Zedek, had lost her beloved older brother; he had just been murdered.On February 6, 2018, Rabbi Itamar Ben-Gal was stabbed to death at a bus stop at the northwestern West Bank junction of Ariel. He was a 29-year-old father of four and a teacher. Rabbi Ben-Gal had dismissed his students early that day so that he could attend a family bris, and found himself standing alone at the bus stop at the wrong time.From a family of six children, Iska was just a year younger than her brother. Itamar was her mentor, her go-to guy, her dearly loved friend. For both, education was a calling.My son Yuval enjoys close relationships with his two younger brothers, a triumvirate born in a three-year span, and with his two considerably older half-sisters. The nature of the sibling relationship, the love and camaraderie, needed no explanation.Sadly, Yuval also had some grasp of mortality, to the extent that our transient existence here can ever be understood. During Operation Pillar of Defense in 2012, an eight-day military operation between Israel and Hamas, he was a six-year-old licking red Angry-Bird popsicle off his sticky fingers, hair still damp from a swimming lesson, when we dove under a stairwell as an air raid siren sounded. We took shelter from an impending rocket attack that luckily landed far away. In 2014, during Operation Protective Edge, the 50-day war between Israel and Hamas in the Gaza Strip, Yuval knew of hundreds of missiles attacks and saw names and faces of some of the war’s victims on television and in the newspaper.Yet, as far as I could gather, these memories of war had blessedly minimal lasting effect on my boy. I had naively hoped that I could similarly shield him from the stabbings, car rammings, and terror attacks that periodically plague the streets of Israel. However, this last stabbing hit too close to home. The news buzzed in a text message on Yuval’s cell phone, and was shared by all the fresh-faced sixth-graders.The day after the attack, Yuval stayed home from school. “I’m not feeling that great,” he said, rubbing his temples. A head cold had worked its way into his heart. He had no strength to unpack emotion with his classmates and the school psychologist.Two days later, we climbed into our car and drove to the Ben-Gal family residence in Rehovot, 40 minutes away from our home in Jerusalem. Reams of people lined the sidewalks: Shiva crowds often explode when tragedy strikes. The balmy weather allowed the Ben-Gals and a sea of mourners to sit in the parking lot, under the glow of artificial light. Outdoors, there was adequate space for the masses coming to comfort Iska, her parents and siblings. The air was thick with sadness and disbelief.Congregating in a dark corner were several familiar faces from the teacher’s lounge at my son’s elementary school. Shira and Sara, Chani and Michal, slumped sadly on white plastic chairs. Instead of light chatter and brown-bag lunches, there was silent sorrow and gloom.Slouched on a mourner’s traditional low stool, intended to mark the grieving over the lost loved one, Iska looked ravaged. When her eyes caught Yuval’s, however, she reached through her pain.“How are you, sweetie?” she asked quietly. He stuffed his hands in the pockets of his grey zip-up sweatshirt and half-smiled.Other sixth-graders trickled in, dragging white plastic chairs into a half-circle. Aviad. Uri. Joey. Yair. Dvir. Amitai. Hadas. Eden. Bezalel. Their earnest faces displayed a sense of being lost, woven into the certainty that they were in the right place. On my son’s face, I saw a thin layer of sadness.What words of comfort can any of us utter in the face of a senseless, heartrending death? Itamar had left behind four children, ranging in age from seven to ten months old. What could one make of the totality of this tragedy?I looked around for Iska’s mother, Shoshi Ben-Gal, a venerated and mythical elementary-school teacher of 35 years, who had retired just a few months earlier. Fifteen people stood in line before me to pay respects. Then it was my turn.“Your incredible daughter is my son’s teacher,” I introduced myself. Lowering my voice, I added, “Even the most critical parents think she’s awesome.”The mourning mother’s face lit up with a knowing grin.“My son and several of his classmates are here. Would you like to meet them?”She nodded.A swarm of children pilgrimaged to the covered side of the parking lot, forming a line in front of their teacher’s mother.“So, kids, what do you have to say about Iska?” asked Ms. Ben-Gal, using the familiar first-name reference to a teacher that’s commonplace in Israel. Ms. Ben-Gal’s face stretched into a smile. For a moment, the pallor of sadness seemed to waft away.“Iska’s the best.”“Totally.”“Duh! Everyone knows we have The-Best-Teacher-In-The-School,” pronounced Uri. Echoes of Yes! Absolutely! For Sure!Ms. Ben-Gal leaned back and grinned knowingly.“Well, I can’t be the one to say Iska is the best. But you can.”It was time to go. We climbed back into the car and headed eastwards to Jerusalem under a cloudless sky.That night, I tucked Yuval in, pressing his red-and-orange down comforter around his body.“How was it?” I asked gently, stroking his hair.“Hard,” he acknowledged. His eyes skated over the white wall.Then he rolled towards me.“Mommy, life is so precious! Let’s go on every vacation, grab every opportunity.” He pulled the soft duvet up to his chin. “Nobody promises you anything.”But I don’t want you to know that yet, I wanted to yell.That shiva call and Iska’s naked pain chipped away at my son’s innocence. But they also carved open a window.Iska had modeled something she had never intended to teach my eleven-year-old: How to be a mourner.He saw how she roused herself to persevere in the face of loss. And he observed the importance of this simple and important Jewish custom called shiva, of the capacity to comfort a mourner with a condolence call. Yuval understood the opportunity he was given to show his cherished teacher something powerful in return: How much he loved her, how deeply he cared.A teachable moment, born through terror, tragedy and heartbreak.