What is the connection between this Parshah and the previous one?
Rashi and Targum Yonasan (on Pasuk 15): Someone who withholds the Matnos Kehunah from the Kohen, will ultimately need to bring him his wife as a Sotah. 1
Why does the Torah repeat the word "Ish"?
Rashi: Because the woman sinned against two 'men' - her husband and Hashem, the "Ish Milchamah". 1
Because, as the Gemara says in Sotah, 17a, the Shechinah dwells between and a man and woman who are meritorious. Rosh - Hashem says, you can deceive your husband, but you cannot deceive Me!
What are the implications of the term "Sisteh"?
Rashi (citing Tanchuma): It is like "Sishteh" (with a 'Shin'), because a people do not commit adultery unless a spirit of Shtus (folly) enters into them. 1
Rashi: It means that the woman strays 2 from the path of Tzeniyus, and her husband suspects her.
What are the connotations of "u'Ma'alah bo Ma'al ba'Hashem"?
Rashi: Refer to Vayikra, 5:15:1:1.
Ramban, Targum Onkelos and Targum Yonasan: Refer to Vayikra, 5:15:1:2.
Seforno: 'She desecrated the holiness of Hashem that He loves with regard to the sanctity of marriage, by hugging and kissing, and the like, another man'. 1
Why did the Torah give Parshas Sotah? We should we say that if there are no witnesses of adultery, she is permitted!
Moshav Zekeinim (9, citing R. Yehudah ha'Chasid): When a man goes to the Mikdash for the Regel, sometimes lewd men remain, and he may suspect lest she sinned without witnesses. Or, he might neglect Aliyah l'Regel, in order to stay to guard his wife.
Rashi says that one who does not give Matanos to a Kohen, will ultimately need to bring his wife (a Sotah) to the Kohen. What is the connection?
Kli Yakar: Rashi wrote that if one does not give Ma'asros, his field will produce a one tenth of what it used to. His wife will suspect that he waxed poor due to Zenus and overseeing harlots - "Ki v'Ad Ishah Zonah Ad Kikar Lechem", "v'Ro'eh Zonos Ye'abed Hon" (Mishlei 6:26, 29:3), so she feels 'I may be Mezanah, just like him.' Kol Eliyahu - she thinks that he is not innocent, so Mei Sotah will not test her, and she will not fear it, and will make herself Hefker. Due to this, he will need to bring her to drink!