1)
What is the meaning of "Chashaf"?
1.
Rashi: He revealed. Radak - this is a metaphor. The salvation of Yisrael will be overt. Also "u'Zero'acha Chashufah" (Yechezkel 4:7) means revealed.
2.
Malbim: This refers to great miracles that man's merits and virtue do not suffice for them.
2)
How will all ends of the land see Hashem's salvation?
1.
Malbim: All will see the great miracles, and know that it is not chance or nature, rather, "Yeshu'as Elokeinu." This corresponds to "Omer l'Tziyon Malach Elokayich" (7).