Two were immortal twice — Two Eternities

The question is to find the meaning of two in "two were immortal twice."

"To us there are two eternities; the one past, the other to come. Ages on ages that had no beginning had rolled away before we came into existence, and endless ages are yet to come." ─ The Countess of Huntingdon's New Magazine (1850)

Two-were immortal twice-
The privilege of few-
Eternity-obtained-in Time-
Reversed Divinity-

That our ignoble Eyes 5
The quality conceive
Of Paradise superlative-
Through their Comparative.
(F.855/J.800)
[1] Two, immortal twice:: a theory of "the two eternities (OED eternity 2b)," eternal past and eternal future.
[2] few:: few people believe that theory.
[3] in Time:: the present time as the division.
[4] Reversed Divinity:: the "eternal past" is a reverse of the eternity in Bible.
[5] our ignoble Eyes:: Dickinson's view on this theory; she didn't believe the eternal life.
[6] quality:: the nature of this theory.
[7] Paradise superlative:: the heaven of God, the supreme happiness of the unknown future.
[8] Comparative:: the comparison of the poor past with glorious eternal life.

"There are two sorts of Eternity; from the Present backwards to Eternity, and from the present forwards, called by the Schoolmen Aeternitas a parte ante, and Aeternitas a parte post. There two make up the whole circle of Eternity, which Present Time cuts like a Diameter."

Carlyle, in his Essays ("Signs of the Times"), has this knowledgeful passage: "We admit that the present is an important time; as all present time necessarily is. The poorest day that passes over us is the conflux of two Eternities, and is made up of currents that issue from the remotest Past, and flow onwards into the remotest Future. ─ Things to be Remembered in Daily Life (1863)

"It has been often said that our knowledge and our being lies between two infinities and two eternities--the infinitely great, the infinitely small, the eternal past, the eternal future." ─ Blackwood's Magazine (1859)

The present thus divides those two eternities now. Through the limit thus ever-present the current of time passes, in a metaphorical sense; and moment by moment the eternity future is transferred to the eternity past, and any portion of time however long must be regarded as nothing in comparison with either. ─ Board of Regents of the Smithsonian Institution (1862)