In Exodus 12:8 (NASB)
They shall eat the flesh that same night, roasted with fire, and they shall eat it with unleavened bread and bitter herbs.
we can read of a roasted lamb that goes together with the unleavened bread and bitter herbs. Then, in Numbers 9:11-12 (NASB)
11 In the second month on the fourteenth day at twilight, they shall celebrate it; they shall eat it with unleavened bread and bitter herbs. 12 They shall not leave any of it until morning, nor break a bone of it; they shall celebrate it in accordance with the whole statute of the Passover.
Does Numbers 9:11-12 assume the existence of the roasted lamb?