There is an amazing R' Tzadok in Resisei Layla (#13) that is worth seeing in its entirety inside, but I just want to discuss a little piece that I quoted elsewhere in a comment. A difficult gemara (Sanhedrin 102b): Rav Ashi was saying shiur and remarked that tomorrow he will discuss "our buddy" Menashe. That night King Menashe appeared to Rav Ashi in a dream and asked how he dared refer to Menashe as his buddy. "Do you even know where to slice bread when you say the bracha of haMotzi?" demanded Menashe. Rav Ashi replied that he did not, and he offered to say over that halacha in the name of Menashe in the shiur if he would teach it to him. Menashe answered that the bread is broken where it first forms a crust, but he then chastised Rav Ashi, "You don't even know where to slice bread and you call me your 'buddy'?!"
The gemara continues with Rav Ashi asking Menashe why he worshipped avodah zarah if he was such a talmid chacham and Menashe replying, but we'll leave that for another time. What's going on in this section of the story? If Menashe wanted to show up Rav Ashi, teaching him that he was not as smart as he thought he was, you would expect him to stump him with some difficult sugya in taharos, maybe a shverr Rambam ; ) -- why ask him davka this halacha of where to slice the bread for hamotzi? Even more perplexing: I can't imagine that Rav Ashi had not said "hamotzi" hundreds of times before -- how did he not know this halacha?
ואמרו בסנהדרין (קב ב) חברא קרית לי מהיכי קשרו המוציא וכו' פירוש כי הברכה שתיקנו חכמים הוא הכרת הנוכח שהשם יתברך זן ומפרנס ונותן דבר מאכל והנאה זו ועל זה מברכין ברוך אתה ה' בנוכח אלא דמכל מקום הסיום בלשון נסתר המוציא וכו' וכן כל הברכות כי הכרת הנוכח הוא בדרך כלל מה שהוא מורשה מאבות. אבל בדרך פרט שיכיר בכל ענין הנוכח מהשם יתברך המורה לו באצבע לומר זה הדרך לכו וגו' כענין שהיה בימות הנביאים זה נסתלק. וזהו ששאל מהיכי קשרו וכו' פירוש אם אתה מכיר בפרט נתינת השם יתברך לחם לכל בשר ולדעת מהיכן הוא ההתחלה שהתחיל השם יתברך להכין לך לחם ומזון שעל זה תברך לו בפרט:
I once wrote an article for my wife's magazine contrasting the mitzvah of challah with the mitzvah of bikurim. All a farmer has to do for bikurim is to go out to his tree and grab one of the fruits that Hashem made the tree produce. However, to fulfill the mitzvah of challah involves harvesting wheat, going through the whole process of turning it into flour, mixing that flour into dough to make bread, and finally seperating off a portion. After all that human effort involved in making the bread, the mitzvah of challah reminds us that it's still food which Hashem provides and not our own handiwork alone.
We all know in a general sense that Hashem provides our sustenance, our parnasa, whatever we need, but it is very hard for to identify with that when it comes down to the specifics, e.g. to feel that Hashem provided me with this computer, this desk, today's job, this minute's task. We start our brachos speaking directly to Hashem -- "Baruch atah..." -- but we end the bracha in a third person generality, "HaMotzi..." When we look at the loaf before us, we recognize in some vague way that Hashem had something to do with it, but we can't really put our finger on and we don't sense Hashem's direct involvement in this specific loaf.
This was Menashe's challenge to Rav Ashi. A bracha is a recognition of Hashem; "Tell me, Rav Ashi, what specific spot in this loaf can you identify as Hashem's gift to you? What specific step in the process of producing this edible loaf causes you to say, "'Aha! That's Hashem's gift?'" The Nevi'im who lived in the generation of Menashe were privy to recognition of Hashem in that way, but Rav Ashi was no Navi.
This was very long, so I decided to treat Rav Ashi's response as a new post