1)
What is "Asher Timtza"?
1.
Radak: What you find in My hand, that I give it to you.
2)
Why did He tell him to eat the Megilah?
1.
Malbim: He saw in it lamentations and fear of punishment. One who accepts Devar Hashem amidst necessity [to avoid] punishment, it is not a Kinyan that clings to his Nefesh and endures with him. He told him to eat it, to the point that it will be in his innards and write it on the tablet of his heart - "v'Sorasecha b'Soch Me'ai" (Tehilim 40:9), "v'Al Libam Echtavenah" (Yirmeyah 31:32).
2.
Alei Shor (2 p.641): He commanded in an expression of eating so he would learn it very well, that his innards would be full of it.
