וְאָכְלוּ אֶת-הַבָּשָׂר, בַּלַּיְלָה הַזֶּה: צְלִי-אֵשׁ וּמַצּוֹת, עַל-מְרֹרִים יֹאכְלֻהוּ.
And they shall eat the flesh in that night, roast with fire, and unleavened bread; with bitter herbs they shall eat it.
בַּחֹדֶשׁ הַשֵּׁנִי בְּאַרְבָּעָה עָשָׂר יוֹם, בֵּין הָעַרְבַּיִם--יַעֲשׂוּ אֹתוֹ: עַל-מַצּוֹת וּמְרֹרִים, יֹאכְלֻהוּ
in the second month on the fourteenth day at dusk they shall keep it; they shall eat it with unleavened bread and bitter herbs;
Why are these two commandments phrased similarly but differently, with the first one apparently indicating a tighter coupling between the korban meat and the matza?