1)
Why does the Torah write ha'To'avos ha'Eil" and not 'ha'Eileh"?
1.
Yevamos, 21a: Bearing in mind that 'Eil' means strong (or severe), it implies that there are other Isurei Araos that are less severe ? a hint for Sheniyos la'Arayos (de'Rabbanan). 1
1
See Torah Temimah, note 76. The Gemara brings a second hint from "u"Shemartm es Mishmarti" in Pasuk 30. See Torah Temimah, note 82.