How does this Pasuk fit into the context of the Parshah? What are the connotations of the word "Ki Va Sus Pharaoh"?
Rashi #1: With reference to the following Pasuk, it means that "when the horses of Pharaoh entered the sea..." that is when "Miriam took a drum in her hand...." (15:20)
Rashi #2 (in Teshuvos Rashi, 2511): It means that Miriam took a drum because the horses of Pharaoh entered the sea.
Ramban #1 (citing the Ibn Ezra): It is an intrinsic part of the Shirah - inasmuch as it relates how Hashem made the water crash down on the Egyptians even while Yisrael were still walking along the dry sea-bed - a miracle within a miracle. In fact, they sang it together with the rest of the Shirah. 1
Ramban #2: It is telling us that they sang the Shirah immediately following the drowning of the Egyptians, not the next day or at a later date.
Ramban #3 and Seforno: It is to inform us that Yisrael sang the Shirah while they were still walking on dry land in the middle of the sea, and not after they had come up. 2
Whe does the Torah write "Sus (singular) Pharaoh"?
Refer to 15:1:6:1 & 2.
What are the ramifications of the Pasuk "u'Venei Yisrael Halechu ba'Yabashah b'Soch ha'Yam"?
Targum Yonasan: There, in the middle of the sea, there were springs of sweet water and fruit-trees, and vegetables and sweets on the sea-bed. 1
Interestingly, on the same words earlier in the Parshah, in 14:29, Targum Yonasan made no comment; nor does there seem to be anything in the Pasuk to indicate what he writes here.