“Aaron married Elisheva daughter of Aminadav, sister of Nachshon (from the tribe of Yehudah).” Shmos 6,23
The point of the Torah giving us these details at this time was to show that the tribe representing Royalty and the tribe representing the Priesthood (religious leadership) formed a liaison through marriage. Elisheva was the sister of the outstanding one of the princes of the twelve tribes, Nachshon scion of the tribe of Yehudah. The verse even mentions the background of the mother of Pinchas seeing that Pinchas became a High Priest in due course through his own — rather than merely hereditary — merit. It is customary in Scriptures that the mother of the ruling monarchs are mentioned (by name and /or background) For instance: Melachim I 15,2 records the name of the mother of Aviyam King of Yehudah as being Maachah daughter of Avishalom. In Divrei haYamim II 20,31 we are told that the mother of King Yehoshaphat was Azuvah daughter of Shilchi. The reason the Torah identifies the wife of Eleazar as “of the daughters (pl) of Putiel” instead of merely stating her personal name or that she was “a daughter” of Putiel is to indicate that she was descended either from Yitro or from Joseph. According to Sotah 43 there was some doubt if this lady was related paternally or maternally respectively to descendants of Yosef/Yitro respectively.
“it turned into a snake.” Shmos 7,10
This was the first of the many miracles Moses performed for Pharaoh. The word תנין, means serpent; we know this from verse 15 where G-d referred to Moses’ staff as having turned into a נחש, a snake. The reason the staff turned into a snake and not into some other animal was that the snake had been the first creature to introduce sin by seducing Chavah with its tongue. Pharaoh had also sinned with his tongue, when he refused to recognize the existence of the G-d of Israel and used this pretext to add that he was not obligated to obey a deity he had never heard of. Just as the serpent at the time had been punished, so Pharaoh starts being punished.
It has become accepted norm that when one slanders G-d or His existence, one is bitten by snakes as we know from BeMidbar 21,5 “the people spoke out against G-d and Moses“ which is followed by (21,6) ”G-d sent fiery serpents against the people and they bit the people.” Furthermore, just as a snake can make itself rigid and wriggle out of unpleasant situations, so Pharaoh squirmed and on other occasions remained rigid in order to avoid having to obey G-d’s wishes. Whenever the plagues got the better of him, he seemed to relent in order to gain relief only to renege in the hope that G-d had exhausted His power. He would resume his obstinate stance of refusing to let the Israelites go. The reason that this נחש is called תנין in our verse is that Pharaoh has been referred to elsewhere as the התנים הגדול הרובץ בתוך יאוריו, “the great sea-monster that crouches within its rivers” (Ezekiel 29,3). The word תנין here contains a hint that just as the staff of Aaron swallowed all the staffs of the Egyptian magicians so the sea (G-d) would swallow Pharaoh and his army at the sea of Reeds.
“seven days were completed.” Shmos 7,25
The Torah spells out that the duration of the first plague was seven days, the length of time a menstruating woman is bleeding or is considered impure due to bleeding. The ritual state of the Egyptians was comparable to that of a menstruating woman. The Torah did not bother to give us data for the length of subsequent plagues as they lasted seven days unless otherwise reported. The interval between one plague and the next was 21 days so that a plague and its aftermath lasted approx. a month. We find this confirmed by Rabbi Eliezer Hakalir in his liturgical poem (recited in Ashkenazi congregations on the eighth day of Passover, commencing with the words מה מועיל רשע רשע בעליו) He says there that a full month was allocated to each plague and that three quarters of the month was allowed for warning and waiting. The fourth part of the month was the actual duration of the plague.
הנה יד ה' הויה, “here the hand of the Lord is about to be, etc.” Shmos 9,3
In introducing the fifth plague the Torah mentions “the hand” of G-d, the word הויה representing the attribute which forms the last letter ה in the Ineffable Name, the tetragrammaton. This is a name which allows for 12 permutations [different spellings using the same letters, a widely accepted kabbalistic method.]. The words זה שמי לעולם, in 3,15 provided an allusion to this concept, the word לעולם hinting at concealed methods of writing this name. Seeing that this was the fifth plague, the Torah makes a point of listing five species of animals which would be afflicted, i.e. horses, donkeys, camels, cattle and flocks.
