1)
What is "Sichi"?
1.
Radak: It is the telling of the hardships. The same applies to "Arid b'Sichi" (55:3).
2)
Who is the enemy?
1.
Rashi: These are the officers who counseled against Daniel - "Edayin Sarchaya va'Achashdarpenaya Havu va'Ayin Ilah Lehashkachah l'Daniel" (Daniel 6:5).
2.
Radak: It is Sha'ul, who wanted to kill David.
