Haven't you learned by now [not to] take[] things out of context?
In Isaiah 51 the prophet is speaking to the Jews. . .
you are making two mistakes 1) ... starting with line 4 and not line 1


As mentioned in the first line of Reply No. 21, the appointed text did begin with verse 1. 
Only verses 4-6 appeared to me to pertain to gentiles, so I only quoted those.

I regret that what I mentioned in the last previous post does seem to be at work here. 
Granted, God here is speaking to Jews. 
But one cannot honestly ignore the points at which God speaks about gentiles:

4 Pay attention to Me, My people; give ear to Me, My nation; for instruction will come forth from Me
and My judgement will be a light for peoples, to whom I will give rest.
5 My righteousness is near; My salvation has gone forth;
My arms will chastise nations; the islands will put their hope in Me and will trust in My arm.
6 Lift up your eyes to the heavens, look at the earth below ---
for the heavens will dissipate like smoke, and the earth will wear out like a garment, and its inhabitants will die, as well;
but My salvation will be forever and My righteousness will not be broken.


"My judgment will be a light for peoples, to whom I will give rest."
"The islands will put their hope in me."

I certainly cannot question that God will chastise nations.  I note that the text does not say, "chastise the nations," nor "chastise all nations."  There are "peoples" to whom God's judgment will be light, "peoples" to whom God will give rest, and "islands" that will hope in God.

This passage, even in context, is not solely about Jews.

P.

“What I admire is honesty and truth, no matter who, or what, the sources are.”
— Uri Yosef