1)
When did Shmuel say this to Yisrael?
1.
Radak: It is when they first requested a king. 1
1
Surely, he learns from verse 19, which says "today you rejected your G-d." (PF)
2)
Why did Hashem say so to Yisrael?
1.
Malbim citing Mahari: It was to warn them. I do not willingly give to you a king, not due to your needs, rather, because you requested it, due to despising Malchus Shamayim.
3)
Why did Hashem mention His salvations of Yisrael?
1.
Malbim: You cannot say that you chose a king because Hashem cannot save you. I took you from Egypt, and from oppressors afterwards.
