1)
Why did he say "Ra'isah"?
1.
Malbim: Refer to 35:22:2:2.
2)
Why did he say "Al Techerash"?
1.
Radak: Do not be quiet to my scream; do not act like a Cheresh. Rather, answer me and save me, for You saw their mockery and talk about me.
2.
Malbim: They say that they saw matters that they did not see. I have no proof against them. Only You, Hashem, saw the Emes, and You are a witness. Therefore, do not be quiet - testify the truth! This is "Al Tirchak"; wage my quarrel, to inform that the Emes is with me!