Shrunk back from what?? The problem is posited as a house that needs to be built, an army that must be faced. When faced with this situation, you can't count your cost and give up.
You have to count your cost, and ask for an extension of the deadline, terms of peace.
Hebrews 3
7So, as the Holy Spirit says:
“Today, if you hear his voice,
8do not harden your hearts
as you did in the rebellion,
during the time of testing in the wilderness,
9where your ancestors tested and tried me,
though for forty years they saw what I did.
10That is why I was angry with that generation;
I said, ‘Their hearts are always going astray,
and they have not known my ways.’
11So I declared on oath in my anger,
‘They shall never enter my rest.’ ”
b
12See to it, brothers and sisters, that none of you has a sinful, unbelieving heart that turns away from the living God.
13But encourage one another daily, as long as it is called “Today,” so that none of you may be hardened by sin’s deceitfulness.
14We have come to share in Christ, if indeed we hold our original conviction firmly to the very end.
15As has just been said:
“Today, if you hear his voice,
do not harden your hearts
as you did in the rebellion.”
c
16Who were they who heard and rebelled? Were they not all those Moses led out of Egypt?
17And with whom was he angry for forty years? Was it not with those who sinned, whose bodies perished in the wilderness?
18And to whom did God swear that they would never enter his rest if not to those who disobeyed?
19So we see that they were not able to enter, because of their unbelief.