The Torah reading on the first day of Rosh Hashanah deals with the birth of Isaac. This was chosen because Sarah became pregnant with Isaac on Rosh Hashanah. (This is also the reason that the haftara tells of the birth of the prophet Samuel, because his mother, Hannah, also conceived on Rosh Hashanah.) The second day's reading is of the binding of Isaac - the Akaida. This was chosen because Abraham's magnificent act of faith in being willing to give up all he held dear and follow the word of G-d, is our "claim to fame." That is, our request to be forgiven for our sins and our request for a good healthy new year, are backed up by referral to Abraham's act of faith. The Jewish nation relies year after on the act of our forefather, Abraham, to be our "credit card" in our prayers for forgiveness and a bright future.
After Abraham passes the Akaida trial successfully we read:
"And He (G-d) said 'Do not touch the lad, nor do anything to him; for now I know that you are G-d fearing and you have not withheld your son, your only one from Me."
For now I know: Rashi: Now I have a response to Satan and the nations who wondered what is the reason for My love for you. Now I have justification, for they see that you are G-d fearing.
Why must Rashi reach for an interpretation - justifying to Satan and the nations? Why couldn't he accept the simple meaning, which is that now, after Abraham passed the trial of the Akaida, G-d knows that he is a man of unconditional and unbounded faith?
Why do you think he needed to interpret the verse as he did?
What's bothering Rashi?
WHAT'S BOTHERING RASHI?
An Answer: The simple meaning - that now and not previously - G-d realized that Abraham was a man of unconditional faith, clearly implies that G-d didn't know this previously. This is not reasonable for several reasons. First of all, G-d is omniscient - all knowing, so "discovering" something new is not G-d's way. Second of all, G-d had already chosen Abraham; He "tested" him with the Akaida not to know if he would withstand the test (as the Ramban point out), because He doesn't need such evidence.
What’s Bothering Rashi?” is produced by the “Institute for the Study of Rashi.”
The Devarim volume of "What's Bothering Rashi?" is now out and should be at your Jewish bookstore. Ask for it. This volume features Rashi and the Ba'alie Tosafos.