I would offer..
Water like blood are used together to represent the unseen work of the Holy Spirit who works with us in us to both will and do His good pleasure. Sign of the first born. Born again believers . Jesus the first of many brothers and sisters (mankind)
I think of two parables. One using David who was in prison like John the Baptist having doubt thirsting for the righteousness of faith, cried for someone? The water of the gospel from the well of living water near the gate of Bethlehem. . Bethlehem. meaning the city of bread .
The father working in three mighty men as apostles sent the three (three establishing the end of the matter) A picture of the gospel doing it work putting ones own life in jeopardy to do the will of the unseen father
Without parables Christ, unseen, spoke not.
At that time David was in the stronghold, and the Philistine garrison was at Bethlehem. David longed for water and said, “Oh, that someone would get me a drink of water from the well near the gate of Bethlehem!” So the Three broke through the Philistine lines, drew water from the well near the gate of Bethlehem and carried it back to David. But he refused to drink it; instead, he poured it out to the Lord. “God forbid that I should do this!” he said. “Should I drink the blood of these men who went at the risk of their lives?” Because they risked their lives to bring it back, David would not drink it. 1 Chronicles 11: 16-19
David by faith looked ahead by faith to the work of the cross giving honor to His father .
The other parable again looking to the first born. It occurred when Moses refused to circumcise the first born using Gershom to represent the Son of Man Jesus . (NIV bridegroom of blood ) (King James bloody husband )
Again using blood or water as a metaphor of the unseen work of the Spirit .
‘This is what the Lord says: Israel is my firstborn son, and I told you, “Let my son go, so he may worship me.” But you refused to let him go; so I will kill your firstborn son.’”At a lodging place on the way, the Lord met Moses and was about to kill him. But Zipporah took a flint knife, cut off her son’s foreskin and touched Moses’ feet with it. “Surely you are a bridegroom of blood to me,” she said. So the Lord let him alone. At that time she said “bridegroom of blood,” referring to circumcision. Exodus 4: 23 -26
The gospel of grace in respect to our bloody huand sufering before had giving the a living hope /Like ours that loks back the rent veil. It as a metaphor represented the foreskin of our savoir and Lord.
I think a person could say those saints believed God after hearing the good news giving them a vision looking ahead we look back to that demonstration .Receiving the end rom the very beginning. Knowing if he begun the good work of salvation in us he will finish it. He is our confidence .We put no confidence in the things seen, the temporal. We rather walk by faith or mixing the two .
Receiving the end of your faith, even the salvation of your souls. Of which salvation the prophets have enquired and searched diligently, who prophesied of the grace that should come unto you: Searching what, or what manner of time the Spirit of Christ which was in them did signify, when it testified beforehand the sufferings of Christ, and the glory that should follow. 1 Peter 1:9-11
I would think a Beautiful picture of the working of the gospel.