Rashi writes: "Noach was afraid to resume... until HaSh-m assured him." How is this derived from the verse?
Gur Aryeh: The word "Hineni" means, "I concur with that which you might say." This shows that Noach was afraid, and HaSh-m reassured him.
HaSh-m's opening words of His covenant with Noach were, "And as for Me," as if in response to Noach's fears. What was Noach afraid of?
Rashi: In response to Noach's initial reluctance to have children, based on the fear of another Flood, HaSh-m already promised him that He would never again destroy the world. Noach's fears persisted however, 1 so HaSh-m agreed to clinch His promise with a covenant, and even showed him a sign.
See Sifsei Chachamim.
Rashi writes: "until HaSh-m assured him... and so He did. Finally, He said [to Noach], I agree to affirm and strengthen my assurance with a covenant, and I shall give you a sign." What are the different stages of HaSh-m's covenant to which Rashi refers?
Gur Aryeh: HaSh-m had originally assured Noach that there would not be another Flood (8:21-22). 1 "Finally," i.e. in this verse, HaSh-m strengthened this assurance to the level of a covenant (Bris) 2 , and even gave the rainbow as a sign.
Although that verse states, "And HaSh-m stated to Himself," according to Gur Aryeh, HaSh-m had already informed Noach of this as well. (See Ibn Ezra to 8:21; also see Ramban loc.cit.)
Rashi writes: "... I shall give you a sign." Why was this last stage necessary; didn't HaSh-m already take an oath to this affect (Rashi to 8:21)?
However, in Bava Basra 74a the Gemara does mention the possibility that the oath regarding the Flood could be annulled. (CS)
רש"י: שהיה נח דואג וכו': מנין שנח דאג?
גור אריה: "הנני" פרושו 'אני מסכים למה שתאמר', ומכאן שנח דאג עד שהבטיחו ה'.
רש"י: עד שהבטיחו הקב"ה...וכן עשה. ובאחרונה אמר לו הנני מסכים וכו': מה פרוש דברי רש"י?
גור אריה: "עד שהבטיחו הקב"ה" לעיל (ח,כא)- "לא אוסיף לקלל", "וכן עשה" כפי שכתוב שם, "ובאחרונה"- כאן, "אמר...הנני" ונתן לו אות.
רש"י: שהיה נח דואג וכו': והרי כבר נשבע לו הקב"ה על כך (לעיל, ח,כא)?
גור אריה: שבועה אפשר להתיר, ולכן נתן לו אות.