He and Isaac had just enlisted, and much to Nadav’s surprise, they had grown apart each day since they had left home, their uniforms in the trenches wrapping and separating them like sheaths of armor. In private, in the few seconds available each day, Isaac still recited his daily prayers, silently, morning, afternoon, and evening. Nadav saw his face, tight-lipped and cold, and knew what he was doing. But he refused to join him.

On that morning, though—the morning Nadav remembered as he climbed up on the white-painted child’s chair, taking the rope in his hands—the attack had begun. Isaac and Nadav were positioned along the edge of the outermost trench, firing on orders from a distant blaring commander, separated from their fellow troops by a part of the trench and well beyond anyone’s view. Poised with his machine gun, Nadav saw Isaac reaching into his olive green bag out of the corner of his eye, pulling out a small satchel made of black velvet and taking something out of it.

“Isaac, what are you doing?”

During a moment’s respite, Isaac had ducked down into the trench, unbuttoned the left sleeve of his fatigues, and pushed it up above his elbow, revealing his pale, hairy arm. He drew his eyebrows together in fierce concentration, positioning the little lacquered box on his biceps and twisting the leather strap around his arm and hand, then placing the other box on his head with its straps encircling his forehead, and finally wrapping the rest of the long strap from his hand three times around his middle finger as he muttered the appropriate biblical verses to himself: “I will betroth you to me forever. . . . I will betroth you to me in righteousness. . . .”

“Isaac, what are you doing?”

Isaac adjusted the circle of leather straps around the top of his head, stretching the leather a bit as he pulled it down much lower and tighter around his head than usual. The black lacquered box sat on his forehead like a gemstone in a crown. “What does it look like I’m doing?” he spit back.

“You’re crazy,” Nadav told him. “We’re going to have to pull out of here. They’re going to have us abandon this trench in the next quarter of an hour, probably even sooner.”

“That’s why I’m doing it,” Isaac answered. The shelling was getting closer. Fully garbed in his tefillin and now beginning to recite the daily morning prayers, Isaac picked up his machine gun and put himself on guard again, still praying.

“How can you aim with that thing on your hand?” Nadav asked.

Isaac paused in his prayers and looked up at Nadav, allowing Nadav’s eyes to sink into his before answering:

“How can you aim without it?”