Beis Hillel says that this second chapter of Hallel, which recalls the Exodus, is also recited at this point at the end of Magid; whereas Beis Shamai recites it only later. What is the reasoning behind each opinion?
For our index of the commentaries on this chapter of Hallel, see the Mafteach to Tehilim section on our site, beginning here:
How did the tribe of Yehudah merit to become "Hashem's holy [portion]," at the splitting of the sea?
1. Mafteach to Shemos 14:22:1:1, section b
How does the word "va'Yanos," allude to what merit it was, which caused the sea to flee from before the Bnei Yisrael?
There seems to be a contradiction here - did the sea flee before Yisrael, or from before Hashem?