On the night of May 28, 1912 and in the early morning hours of May 29, 1912, Abdu'l-Baha could not overlook the fact that his own father had departed from this world at 3 am on May 29, 1992.
Here is a passage that Abdu'l-Baha is sure to have read during the course of that night:
Be not dismayed, O peoples of the world, when the day-star of My beauty is set, and the heaven of My tabernacle is concealed from your eyes. Arise to further My Cause, and to exalt My Word amongst men. We are with you at all times, and shall strengthen you through the power of truth.
—Bahá’u’lláh, Gleanings, p.137