I didn't say it was from the Law. I said it was an "ancient practice."
iakov the fool
I covered such an assumption, by the scripture I posted.
25 The baptism of John—where was it from? From heaven or from men?”
And they reasoned among themselves, saying, “If we say, ‘From heaven,’ He will say to us, ‘Why then did you not
believe him?’ 26
But if we say, ‘From men,’ we fear the multitude, for all count John as a prophet.” 27 So they answered Jesus and said, “We do not know.”
And He said to them, “Neither will I tell you by what authority I do these things.
Matthew 21:25-27
Jesus said they did not believe
him, John the Baptist, the one who introduced water Baptism
John the Baptist introduced Baptism in Water for repentance.
The baptism of John—where was it from? From heaven or from men?”
"From men" covers your "ancient practice" theory.
and again
30 The baptism of John—was it from heaven or from men? Answer Me.”
31 And they reasoned among themselves, saying,
“If we say, ‘From heaven,’ He will say, ‘Why then did you not believe him [John]?’ 32 But if we say, ‘From men’”—they feared the people,
for all counted John to have been a prophet indeed.
3 And he said to them, “Into what then were you baptized?”
So they said, “Into John’s baptism.” Acts 19:3
“The law and the prophets
were until John.Since that time the kingdom of God has been preached, and everyone is pressing into it.
Luke 16:16
JLB