Why does it say "l'Einei Kol ha'Kahal"?
'Rashi': He gathered everyone - "va'Yakhel David" (28:1), and blessed them for giving willingly.
Why did he mention Yisrael more than the other Avos?
'Rashi', Radak, based on Bereishis Rabah 70:2: I vowed, like Yakov - "va'Yidar Yakov Neder Leimor" (Bereishis 28:20). Radak - "Leimor" teaches that Yisrael will vow at the time of their distress (Pesikta Zutresa Bereishis 28:20). Since he was first, all who vow are attributed to him - "Asher Nishba la'Shem Nadar la'Avir Yakov" (Tehilim 132:2)
Radak: Yakov first said to build Beis Elokim - "veha'Even ha'Zos... Yihyeh Beis Elokim" (Bereishis 28:22)
Malbim: It is because Yakov saw the ladder in Har ha'Moriyah, and said "Ein Zeh Ki Im Beis Elokim", and there Hashem showed to him the Bayis and Sha'ar ha'Shamayim.
Why did he say "me'Olam Ad Olam"?
'Rashi': David said, there was one convert, Yisro, among 600,000 [Yisraelim], and he said "Baruch Hashem Asher Hitzil Eschem" (Shemos 18:10) - it was a great shame to all of Yisrael [that they did not bless Hashem]. I will bless Hashem more than Yisro!
