Because I answered your inquiry. Got it.
That is ridiculous nonsense. Show the scripture that says water baptism was a sign to the Jews.
For one boasting of being God's Truth you have much to learn from the real God's Truth.
Throughout Israel’s history, signs were a part of the nation of Israel's birthright.
Deuteronomy 26:8 - “And the Lord brought us forth out of Egypt with a mighty hand, and with an outstretched arm, and with great terribleness, and WITH SIGNS, AND WITH WONDERS.”
When Moses was commissioned to deliver Israel from Egypt, he was given two specific SIGNS designed to motivate the nation to believe.
In Exodus 29 we learn that ordination into the priest’s office was through a ceremony that included two very important rites: first, a washing with water [water baptism]; second, an anointing with oil.
These two things are beautifully united when our Lord, Israel’s true High Priest (Heb. 3:1), came to be baptized of John in order “to fulfill all righteousness.”
John the Baptist, preached a national baptism to the nation Israel as a means of national repentance and preparation to be the kingdom of priests God ordained that favored nation to be.
In Acts 2:38, Peter echoes John’s words.
Just as circumcision is the sign of the ever Abrahamic Covenant, and the Sabbath is the sign of the Mosaic Covenant, so water baptism is the sign of the Davidic Covenant.
Now, you can agree with God's Truth or you can reject it. It is no skin off my back.