"I am sure you’ve noticed by now that I’ve been talking about Zen as a religion...In other words, He found That Which Is. What the Christians call “God” and Mohammedans call “Allah”, the Buddhists call variably: That Which Is, the Lord of the House, the Cosmic Buddha, the Eternal, Amida Buddha, the Immaculacy of Emptiness, Vairocana Buddha, the Unborn, etc."
Yes, well... It's not quite like that though, is it?
The (completely out of context) quote is from the Udana (Exclamations), a collection of short teachings by the Buddha that end with a statement/exclamation.
The teaching referred to is this one:
http://www.accesstoinsight.org/tipitaka ... .than.html
Ud 8.3 PTS: Ud 80
Nibbāna Sutta: Unbinding (3)
translated from the Pali by Thanissaro Bhikkhu
I have heard that on one occasion the Blessed One was staying near Sāvatthī at Jeta's Grove, Anāthapiṇḍika's monastery. And on that occasion the Blessed One was instructing, urging, rousing, & encouraging the monks with Dhamma-talk concerned with unbinding. The monks — receptive, attentive, focusing their entire awareness, lending ear — listened to the Dhamma.
Then, on realizing the significance of that, the Blessed One on that occasion exclaimed:
There is, monks, an unborn — unbecome — unmade — unfabricated. If there were not that unborn — unbecome — unmade — unfabricated, there would not be the case that escape from the born — become — made — fabricated would be discerned. But precisely because there is an unborn — unbecome — unmade — unfabricated, escape from the born — become — made — fabricated is discerned.
1. Some scholars have argued that the term "unborn" cannot be used to distinguish unbinding from transmigration, as there are discourses (such as SN 15.3) stating that transmigration itself has no beginning point, implying that it too is unborn. Thus they argue that in this passage the term ajātaṃ, although a past participle, should be translated as, "without birth." However, this argument is based on two questionable premises. First, it assumes that unbinding is here being contrasted with transmigration, even though the passage simply contrasts it with the fabricated. Secondly, even assuming that the phrase "the born — the become," etc., is a reference to transmigration, the scholars' argument is based on a misreading of SN 15.3. There, transmigration is said to have an "inconceivable" or "undiscoverable" beginning point. This is very different from saying that it is unborn. If transmigration were unborn, it would be unfabricated (see AN 3.47), which is obviously not the case. Thus, in translating this term to describe unbinding, I have maintained the straight grammatical reading, "unborn."
2. Iti 43 gives this exclamation as the synopsis of a Dhamma talk, followed by this verse:
The born, become, produced,
made, fabricated, impermanent,
fabricated of aging & death,
a nest of illnesses, perishing,
come-into-being through nourishment
and the guide [that is craving] —
is unfit for delight.
The escape from that
a sphere beyond conjecture,
the sorrowless, stainless state,
the cessation of stressful qualities,
So, as can be seen quite clearly, the Buddha was not talking about a god/entity/deity, he was talking about Nirvana as being "Unborn, Undying, Unchanging, Uncreated".