Boyd’s Bible Dictionary:
A part of the passover feast (Ex. 12:8).
Concise Bible Dictionary:
No particular herbs are specified by name, indeed the word “herbs” is added in the AV, so that it is literally “bitterness.” The paschal lamb was to be eaten with “bitter herbs,” doubtless signifying the sense in the souls of those partaking that it was for their sins the victim was slain (Ex. 12:8; Num. 9:11).