I had learned about the lingam only a few hours before I posted about it. Even though I'd been with Sai Baba in the early 1980s I'd had few interactions with his devotees in the intervening years and knew little about the situation around him since I'd been with him.
And so I as much stumbled across information about the lingam. This happened when I suddenly found myself wondering why it was that Sathya Sai Baba had always manifested egg-shaped lingams on Mahashivaratri, during the years he had manifested them on that night most sacred to followers of Shiva. In the 1980s I had seen Shiva lingams manifested by a Shaivite Yogi on Mahashivaratri and they looked like, well, like Shiva lingams. Not egg-shaped.
The question about Sai Baba's egg-shaped lingams had occurred to me at the time but as I had no interest in the Shaivite sect (or Sai Baba's lingam materializations), the question went to the back of my mind until the night of June 1, 2019. I took to the internet in an attempt to get an answer and immediately came across the story of the Golden Heart Lingam and the photographs of it. I did not continue to search; I felt I had gotten the answer to my question, if only I could understand it.
Since then my mind has returned many times to the golden lingam and the mystery of why Sai Baba manifested it at that time. It certainly wasn't during Mahashivaratri and did not happen at the Prasanthi Nilayam ashram where his lingam manifestations, at least the public ones, had always occurred. It had happened in the auditorium during a Brindavan college summer course.
And while the person who reported on the incident didn't specifically say, it didn't seem that Sai Baba had manifested the lingam from his stomach, as happened with the Mahashivaratri lingams. My assumption, from the description of the incident (see below) is that he had simply materialized it with a wave of his hand with no warning.
By why? And why then? What, if anything, was so special about the year 1991 to merit such an extraordinary gift of grace from Sai Baba?
Based on what is written in Wikipedia about this golden cosmic egg (see below), and on what I learned during my time in Sai Baba's presence, I'm going to make a couple guesses as to the answers. I emphasize that these are just guesses.
First, I think he manifested the lingam to signify that his formal mission in the Sathya Sai Baba incarnation had ended at that time.
If my guess is correct, of course, the Sai Baba form continued on for several more years after 1991 and continued to be available to large numbers of people, but my guess is that May 5, 1991, was when the emanation had accomplished what it was created to do.
Second, and given what has been written about the Golden Heart Lingam, I think his materialization of it was to make it explicit that Sathya Sai Baba had been nothing less than a human incarnation of the Vedic god Prajāpati, who came to be known in 'Hinduism' as Brahma, the god of creation.
Supposedly Brahma never incarnates in human form. But there are exceptions to every rule and my guess is that Sathya Sai Baba represented an exception.
Those are my guesses.
Closeup of a photograph of Sathya Sai Baba holding the Golden Heart Lingam at the time he brought it forth on May 5, 1991
Hiraṇyagarbha (Sanskrit: हिरण्यगर्भः ; literally the 'golden womb' or 'golden egg', poetically translated as 'universal germ') is the source of the creation of universe or the manifested cosmos in Vedic philosophy, as well as an avatar of Vishnu in the Bhagavata Purana. It finds mention in one hymn of the Rigveda (RV 10.121), known as the Hiraṇyagarbha Sūkta, suggesting a single creator deity (verse 8: yo deveṣv ādhi devā eka āsīt, Griffith: "He is the God of gods, and none beside him."), identified in the hymn as Prajāpati. The concept of the "golden womb" is again mentioned in the Vishvakarman Sūkta (RV 10.82).
The Upanishad calls it the Soul of the Universe or Brahman, and elaborates that Hiraṇyagarbha floated around in emptiness and the darkness of the non-existence for about a year, and then broke into two halves which formed the Svarga and the Pṛthvi.
In classical Purāṇic Hinduism, Hiraṇyagarbha is the term used in the Vedanta for the "creator". Hiraṇyagarbha is also Brahmā, so called because it is said he was born from a golden egg (Manu Smṛti 1.9), while the Mahābhārata calls it the Manifest.
See also "I am the Creator of the Hiranyagarbha from which Brahma was born"; November 23, 2019, Pundita blog.