1)
What is the meaning of "Shif'as Yehu"?
1.
Rashi: It is his troop.
2.
Radak: It is the multitude [of people who came with him]. The same applies to "Shif'as Gemalim" (Yeshayah 60:6), " Shefa Yamim Yinaku" (Devarim 33:19).
2)
Why does it say "Shif'as [Ani]" with a Sov at the end?
1.
Radak: The Sov is in place of a Hei, for it is not Samuch. We find like this - "Chachmas va'Da'as" (Yeshayah 33:6), "Im Eten Shenas l'Einai" (Tehilim 132:4), "k'Simchas ba'Katzir" (Yeshayah 9:2) and similar verses.
3)
What is the meaning of "Rakav"?
1.
Radak: It is one who serves one who rides a horse. He rode on his master's horse to greet Yehu.