I don’t consider the old covenant (Old Testament) either vague or imprecise, nor do I consider the new covenant (New Testament) unclear.
I consider the old covenant to be the “old” covenant and the new covenant to be the “new” covenant.
It makes sense to me what you posted about a young woman conceiving being a meaningless statement as it was supposed to designate a “sign” from God. Good point!
1) sign, signal
a) a distinguishing mark
b) banner
c) remembrance
d) miraculous sign
e) omen
f) warning
2) token, ensign, standard, miracle, proof
Therefore the Lord himself shall give you a sign! I think (agree with you) that He would pick something designed to demonstrate His omnipotence as opposed to an everyday occurence.
Yes, thank you.