Today is Pesach Sheni. Those Jews in the desert who were impure and were unable to eat the Korban Pesach asked for a second chance. So Hashem allowed them [and for the generations] to have the Pesach in Iyar.
There is a wondrous Rashi in Bamidbar [9/10] that says the following: פסח שני מצה וחמץ עמו בבית ואין שם יו"ט ואין איסור חמץ אלא עמו באכילתו
Many commentators understood Rashi to be saying that chametz is permitted on Pesach Sheni but when eating the actual korban it is forbidden to eat it together with chametz. The Minchas Chinuch is dumbfounded -where does Rashi get this? Why not? Chametz is only forbidden on Pesach Rishon in Nissan!
The sefer Ambuha Disifree says that the Minchas Chinuch just missed a period. If you put a period after the word חמץ Rashi reads that there is NO prohibition against eating Chametz rather you can even eat it with the Korban Pesach.
The sefer Shaarei Yitzchak on Kiddushin has a long detailed article on this topic at the end of the sefer. Ayain Shom!
And the lesson of the day -even those who are impure and far away from Hashem ["derech richoka" as the pasuk says] have a second chance! :):)
Love and blessings!