For decades, I have saved a shoebox of letters written by a teacher and mentor. She is no longer alive, and it’s a comfort to return to those letters from time to time and feel her presence and her wisdom and humor, through her words. I’m not sure that when she sent them, she had in mind to write toward posterity.

Elana Zaiman sees the potential in writing letters to communicate from the heart and across time. She has coined the term “forever letter” to refer to a letter written intentionally as a statement of meaning, solidifying connection and understanding between the writer and recipient. The letter not only expresses values, lessons learned, love and appreciation, but also acknowledges and honors the recipient.

In “The Forever Letter: Writing What We Believe for Those We Love” (Llewellyn), she guides readers in creating their own letters that spell out what matters most. For several years, she has been leading workshops around the country to help people channel their own values, insights and deep expressions of self onto the page. She suggests that individuals write directly to children and grandchildren and others too, and includes people without families who may want to write to friends.

Zaiman, a sixth-generation rabbi and the first woman rabbi in her family, is inspired by the Jewish idea of preparing ethical wills, a practice going back to medieval times. In her book she explains that parents would write to their children, “stating their prescription for living meaningful Jewish lives by following certain ethical and ritual precepts.” Over time, an ethical literature emerged, including ethical treatises, homiletic works and ethical wills. The first two were written by scholars, while an ethical will could be written by anyone, whether at the end of a life, or when setting off for a big trip.

While the medieval ethical wills elaborated on values and hopes, they also contained an element of commandment, which is not part of a forever letter. The writer of one of these 21st century letters might explain the traditions and how they may have guided a life, but understands that everyone takes the idea of tradition in his or her own way.

“It’s like sharing a mission statement in life, what you try to live by, what you hold dear and what guides you,” Zaiman says in a telephone interview from her home in Seattle, where she serves as chaplain for a Jewish retirement community. She has also led workshops in Wise Aging, a course inspired by the book by Rachel Cowan and Linda Thal. Before moving to Seattle in 1998, she served as a rabbi of Park Avenue Synagogue in Manhattan.

She first heard of the idea of ethical wills when she was 14, when her father showed her a book that collected several contemporary versions. The wills were unsigned, but she was easily able to identify her father’s contribution to the book, which was a letter to Elana and her siblings. She has been mindful of the words he shared all of her life, and the idea of an ethical will has been on her mind since then.

Zaiman writes “The Forever Letter” with compassion, understands the gravity of her subject and leavens it with humor, stories that she tells well and practical advice. Underlying her ideas is her rabbinic training and wisdom. While the very idea of these letters hints at mortality and death, the process of writing — and especially Zaiman’s approach — is life-affirming.

In her teaching and writing, she reaches out to younger elders as well as people in their 70s, 80s and beyond. Among the elder folks she works with in retirement communities, she finds that many speak of no longer having a purpose in life — they still want to give to the world but are more limited in what they can accomplish. Writing a forever letter, she says, helps them feel more valuable.

For younger elders, drafting a letter might be particularly appropriate when a child is going off to college, getting married or having a first child, or it might be geared to aging parents.

“It’s a gift,” she says, “saying what you love most and admire in the people you are writing to, what you see in them that you want to acknowledge.”

Letters might also include blessings, asking (or granting) forgiveness, memories of earlier days, significant experiences revisited and quotes from religious traditions to highlight a belief. The book includes many quotes and stories, from thinkers like Rabbi Abraham Joshua Heschel, Annie Dillard (“How we spend our days is, of course, how we spend our lives”), Joan Didion and her own father, Rabbi Joel Zaiman of Baltimore.

At her workshops, Zaiman will often begin with a discussion and then give people an opportunity to write; she provides prompts, which appear in an appendix to the book, whether as sentence completions (“Here’s what I learned from my parents…”) or questions (“Who are the 10 most important people in your life? Why?”). She’s sure to leave boxes of tissues on the tables, as participants often reach emotional depths.

“You come face to face with who you are and who you aren’t,” she says.

Zaiman recommends that people begin the process with sitting down quietly with a pad and pen. As she says, “A pen goes straight from the heart to the page.”

“You never know what will happen. Something about the process of writing takes you to a different place, a deeper place.”