1)
Who are "Se'afim"?
1.
Rashi: They are people who think about sin. This is like "Lachen Se'ipai Yeshivuni" (Iyov 20:2), "Al Shtei ha'Se'ifim" (Melachim I, 18:21). Se'ifim refers to the thoughts; Se'afim it refers to those who think them.
2.
Radak #1: Some say that it is To'ar (a kind of person), i.e. one with bad thoughts.
3.
Radak #2: I say that it is a noun (thoughts. I hated all thoughts other than Torah.)
2)
How does he express his love of Torah?
1.
Radak: All his thoughts are on it. Malbim - above (97), he said "Mah Ahavti Sorasecha Kol ha'Yom Hi Sichasi" - he speaks only in Torah. Now it adds that he thinks only in Torah. He hates to put other thoughts in his heart.
