JMNT(i)
6 The effect of your boast is not beautiful, fine, ideal or good form. Have you not seen so as to know that a little leaven (or: yeast) progressively leavens (permeates) [the] whole lump of dough (the result of that which has been uniformly mixed and kneaded together)?
7 At once completely clean out the old leaven, so that you folks would progressively be a fresh, new lump of dough with uniform mix-effect, just as you are free from ferment (or: in that you have continued being an aggregation which has been freshly mixed and kneaded together – correspondingly as you are continuing being unleavened ones). For also Christ, our Passover [= Passover lamb], was slaughtered in sacrifice.
8 Consequently, we can (or: should) be continuously keeping and celebrating the Feast (Festival) – not in union with old leaven (or: leftover yeast), neither in union with or in the midst of a leaven of bad quality (worthlessness; ugliness; what ought not to be; malice) and painful misery (hard labor; evil disposition; mischief; wickedness) – but in contrast, in union with and in the midst of unleavened cakes (matzah) of genuineness (or: integrity and sincerity; that which has been tested by sunlight and found to be genuine or pure and unadulterated) as well as truth and unhidden reality.