Here Isaiah describes events that will happen in the future as if they happened in the past. This emphasizes that they certainly will happen.

## Who would have believed what we heard? ##

What Isaiah just found out is so amazing that he wonders if the exiles will believe it. The "we" includes him and those in exile. (See: [[rc://en/ta/man/translate/figs-inclusive]] and [[rc://en/ta/man/translate/figs-rquestion]])

## Who would have believed ##

This question is like the one above, expressing surprise.

## And the arm of Yahweh, to whom was it revealed? ##

AT: "And to whom has Yahweh revealed his power?" (See: [[rc://en/ta/man/translate/figs-metonymy]] and [[rc://en/ta/man/translate/figs-activepassive]])

## For he grew up before Yahweh like a sapling, and like a sprout out of parched earth ##

Here "he" refers to God's servant whom Isaiah compares to a very young tree. This emphasizes that he will appear weak. (See: [[rc://en/ta/man/translate/figs-simile]])