1) HASH-M'S ANGER
QUESTION: The Gemara says that Hash-m's anger lasts for an extremely short moment in time (at most, the length of time needed to pronounce two syllables). Bil'am wanted to curse the Jewish people during that inauspicious moment of Hash-m's wrath. What curse could Bil'am possibly utter in such a short amount of time?
(a) TOSFOS (DH she'Ilmalei) says that as long as the curse would begin during the time of Hash-m's anger, the rest of the curse would also be effective.
(b) TOSFOS gives another answer. Bil'am could have said the word, "Kalem" -- "Destroy them!" in that short amount of time. Tosfos in Avodah Zarah (4b, DH Rega) adds that according to this explanation, Hash-m not only "reversed the curse" (Devarim 23:6) figuratively, but He literally reversed it. Instead of saying "Kalem" ("destroy them"), Bil'am said, "Melech" (Bamidbar 23:21). The letters of "Kalem," when reversed, spell "Melech."
This explains a Gemara in Horayos (10b). The Gemara there teaches that a person should engage in the study and practice of the Torah even if his motives are insincere, for he will eventually develop a sincere motivation. The Gemara demonstrates the value of even an insincere service of Hash-m by the fact that as a result of the 42 sacrifices that Balak offered to Hash-m, he merited to have Ruth among his descendants. Rashi explains that the import of this statement is that David ha'Melech, Ruth's great-grandson, descended from Balak. (See Insights to Nazir 23b.)
This may be the deeper meaning behind the statement of Tosfos in Avodah Zarah that Bil'am's curse of "Kalem" was reversed and became a blessing, "Melech." The very sacrifices which Bil'am had advised Balak to bring in the hope that they would lead to Moav's victory over Israel (represented by the word "Kalem") achieved the opposite result. They led to the birth of David ha'Melech (the "Melech") who later led Israel in the defeat of their enemies, including Moav! (M. KORNFELD)
2) NO ONE CALLED HASH-M "ADON" UNTIL AVRAHAM
AGADAH: The Gemara says that Avraham was the first to call Hash-m, "Adon." Rav Pinchas Altshul of Plotsk (a disciple of the Vilna Ga'on) in SIDUR SHA'AR HA'RACHAMIM uses this statement to explain why our morning prayers begin with "Adon Olam." When we recite "Adon Olam," we invoke the merit of Avraham Avinu.
The Gemara in Tamid (30a) says that an enactment was made in the Beis ha'Mikdash that the Avodah could not begin until someone said, "Daylight has reached Hebron." The purpose of this practice was to invoke the merit of the Avos, our forefathers, who lived in Hebron (Rashi to Yoma 28a, DH v'Iy Ba'is Eima, citing the Yerushalmi.) Just as the Avodah began by invoking the merit of the forefathers, we begin our prayers by reciting "Adon Olam" to invoke the merit of Avraham Avinu.
This is also implicit in the verse we recite every day before the morning prayers, "va'Ani b'Rov Chasdecha..." -- "And I, in Your great kindness, will come into Your house...." We recite this verse before the morning prayers in order to invoke the merit of Avraham Avinu, who was chosen to be the recipient of Hash-m's great kindness. Moreover, we allude to Avraham's attribute of Chesed, for which he earned his position as the forefather of the Jewish people.
It may be added that it is particularly appropriate to mention the merit of Avraham Avinu more than that of the other Avos, since the morning prayers were instituted based on Avraham's morning prayer (Berachos 28b). (M. KORNFELD)