David Eisenhower’s new book, “Going Home to Glory: A Memoir of Life with Dwight D. Eisenhower, 1961-1969,” offers many poignant, illuminating stories. This one stands out:

It was Thanksgiving 1967, and he and Julie, both all of 19, had just gotten engaged.

David Eisenhower knew that his grandfather was fond of Julie Nixon — he called the daughter of his former vice president “an angel” — but he also knew that his grandfather thought marriage should wait until David was older and more “established.” After all, Ike had married Mamie at the ripe and seasoned age of nearly 26.

Moreover, Ike was more than “Granddad.” He was General Eisenhower, supreme commander of the Allied forces in Europe during World War II, two-term president of the United States — principled, disciplined, often stern and forbidding.

For two days, David procrastinated, trying to summon the courage to break the news. On the day David was to return to college, Ike summoned him to his bedroom. Grandfather and grandson made perfunctory small talk but mostly sat in uneasy silence. Thirty minutes passed.

“I choked,” David recalled during a recent interview at his home in Berwyn. “I couldn’t do it.”

Back at Amherst, David received a letter from the five-star general, acknowledging his grandson’s engagement to Julie and registering his delight: “You are both the kind of people who will, throughout your lives, enrich America. Moreover, a love, shared by two young and intelligent people, is one of heaven’s greatest gifts to humanity.”

Ike concluded by declaring: “I’m not only proud that you are my grandson, but my friend as well — to whom I give my deepest affection.”

“A treasure,” David Eisenhower calls the letter today. “My greatest gift.”

While Ike may have been formidable and undemonstrative, he could also be compassionate and tender. While he may have been famous for his winning grin and passion for golf, he was also deeply principled and thoughtful. At news conferences, especially after his 1957 stroke, he may have seemed awkward and tongue-tied, but, on paper, he expressed himself with eloquence and was capable of phrases of biblical majesty.

Some books are written from the head; others, from the heart. “Going Home to Glory” (Simon & Schuster, $28), which David Eisenhower composed with ample assistance from his wife, Julie, is both, though it tilts pleasingly toward the latter.