Was he satiated with bitter herbs?
Rav Sadya Gaon: It is as if he was satiated.
Ibn Ezra: The prefix Beis in ba'Merorim is extra 1 , like "va'Tashkemo bi'Dma'os Shalish" (Tehilim 80:6). In place of bread and water (which normally satiate people), I had Merorim and La'anah.
Palgei Mayim: Keneses Yisrael says, He made me sin greatly. Maror is initially sweet, and at the end it is bitter 2 . Therefore, sin is compared to Maror.
I.e. the verb 'Hisbi'a' does not obligate the prefix Beis in front of the matter that satiates him, e.g. "Asbi'a Lechem" (Tehilim 132:15). (PF)
Yerushalmi Pesachim (2:5, 18a) says so about Chazeres. If Romaine lettuce is left to grow about a month after it is usually harvested, it produces a new set of bitter leaves. See note 24 in appendix to Point by Point Outline to Pesachim 39a (www.dafyomi.co.il/Pesachim/points /ps-Pesach-appendix.htm#24).
Why does it add "Hirvani La'anah"?
R. Avigdor: We eat Maror on Pesach, and the same night of the week [that year] will be Tish'ah b'Av, on which "Hirvani La'anah." (Refer to 1:2:2:8*.)
Palgei Mayim: The punishment is compared to La'anah, which is bitter at the beginning and at the end.