The resulting manuscript tracks the emotional, spiritual and physical journey of someone acutely conscious of death. For Gaber, however, the writing process may have been even more valuable than the end product.
"It allowed me to stay more in the moment and not worry so much about the future," the 38-year-old San Franciscan said recently, sitting in his sunny Castro District studio apartment crammed with Judaica and plastered with gay-pride rainbows.
On Thursday, the annual ritual known as the Counting of the Omer began as always on the second night of Passover. The period marks the 49 days between Passover, which celebrates the Exodus from Egypt, and Shavuot, which honors God's giving of the Torah at Mount Sinai.
In Jewish tradition, these seven weeks symbolize the transformation of a haggard band of slaves into a people prepared to accept God's revelation. Today, some Jews also approach the Counting of the Omer as a time to delve into their consciousness.
"The counting is almost like climbing the mountain — climbing Sinai — to reach God, to hear God's word," said Gaber, former assistant executive director at the Jewish Community Center of San Francisco. "It's getting your body and soul and psyche ready."
For each of the 49 days last year, Gaber meditated at least 30 minutes. He prayed and read psalms of healing. He made his seventh trip to Jerusalem, where he spent most of the seven weeks.
He concentrated heavily on the kabbalistic view of the 49 days. In this Jewish mystical perspective, each day of the counting manifests a different attribute of God and focuses energy into a distinct area of the body. On the first day, for example, Jews concentrate on God's love and on the energy of the right arm.
Gaber set up his journal like a page of the Talmud, with a section in the middle that briefly explains the spiritual aspect of the day. This middle section is surrounded by five others, filled in each day with a psalm, a quote, a body part, a thought on self-forgiveness and a reflection on living with AIDS.
His thoughts range from fearing he'll succumb to AIDS-related dementia to pondering whether similarities exist between the AIDS epidemic and the Holocaust.
Sometimes he simply asks, "What will I do with the life energy still remaining in my body?" or "Who'll remember me on my yahrzeit?"
After praying at the Western Wall one evening with a half-dozen different minyans, he comments:
"What amazed me was how quietly these groups dissolved after the completion of the davening. It seemed that the members were again strangers, each going his own way.
"I loved the intimacy and grieved at how quickly it disappeared. In many ways this is how my community of gay men in San Francisco fell apart, so many deaths related to AIDS. I mourn this loss and feel a giant gap in my life."
For Gaber, Counting the Omer is "as Jewish and natural as lighting Shabbat candles."
Born in Boston, he was raised in an Orthodox home and attended Lubavitch day schools for 12 years.
As an adult, Gaber moved outside the Orthodox world. He came to San Francisco in 1979 to earn his master's degree in social work. He worked at the JCC of S.F. from 1981 until shortly after he was diagnosed with full-fledged AIDS on Shavuot 1993.
Over the years, he became involved in Congregation Sha'ar Zahav, a Reform synagogue with outreach to gays and lesbians. He taught classes at Reform and Conservative synagogues. He explored Buddhism, Taoism and Hinduism.
Just over a decade ago, he began an independent study toward rabbinic ordination through the Jewish Renewal movement and one of its leaders, Rabbi Zalman Schachter-Shalomi.
Schachter-Shalomi is the one who pushed Gaber to begin the journal project and then ordained Gaber as a rabbi last September.
Gaber credits spiritual work, such as this project, with helping to sustain him through his illness.
"I learned I could independently — without a teacher or rabbi or doctor or acupuncturist — be aware of my body and tune into it," he said.
Today, his T-cell count has dropped to 12. A healthy person's infection-fighting T-cell count ranges from 800 to 1,200.
Gaber looks thin but otherwise fine. Yet he frequently suffers from fevers and nightsweats. He tires easily. He has a chronic digestive disorder called Crohn's disease. He has anemia, nerve damage and colon ulcers — all side effects from the 40 pills he downs daily.
He already has planned his funeral.
But during his project last year, Gaber also learned a lesson about focusing too much on death.
He had scheduled an appointment with a Chassidic rabbi in Jerusalem to ask for a blessing.
During the 4 a.m. meeting, Gaber told the rabbi he had AIDS. The rabbi went into a meditative trance for a few minutes and then instructed Gaber to lay tefillin every day, study about the tefillin, and try to observe Shabbat as much as possible. And he offered an insight that Gaber has not forgotten.
"Doctors don't know how long we'll live," the rabbi told Gaber. "Only God knows this."