Hope deferred maketh the heart sick: but when the desire cometh, it is a tree of life.
Hope is the desire of something good, accompanied with an expectation of obtaining it, with the belief that it is obtainable.
However, the time frame until the possession of that which we desire and expect, isn’t desirable.
Like the verse above; Hope differed (delayed) will make the heart sick. That is to say,
if that which we hoped for; if it is not soon revealed or received as expected, a delayed any length of time before the possession, the mind becomes uneasy, the heart sinks into doubt and discouragement, therewith, the individual becomes dispirited without hope. Forfeiting the desire of that which they hoped for. Thereby giving up all hope of enjoying the desired blessing; that is ahead, whether it be deliverance from evil, or the possession of the heart’s desire.
However, when the desire cometh, it is a tree of life.
Note, the adverb “when” is used, not "if" the desire comes. Instead, when it comes. In other words, though it tarry, but it shall come, and when it does, it is a tree of life.
This speaks of the tree of life, as it was in Eden's garden; an unspeakable pleasure and delight, while sustaining and never depleting.
Henry said, nothing is more grievous than
the disappointment of a raised expectation, though not
in the thing itself by a denial, yet in the time of it by a
delay. Nothing is more grateful than to enjoy that, at last,
which we have long wished and waited for.
So then, though we have not seen it yet, but let us continue to hope for it, by faith.
Longer valley, big wings
Though I walk through the valley, but the longer the valley, the fuller the wings that awaits me, and the furthest I shall fly. Leaving the valley beneath, and reaching forth for the glory of the skies.