[Rabbi Avraham] haMalakh used to bake matzahs the day before Passover and sent them to his father the holy Magid. They asked the Magid: “Usually, the custom is that the father sends his son matzahs not the other way around.” The Magid replied: “To be so careful of even a minuscule amount of leaven can only be accomplished by an angel [alluding to haMalakh] – that is why I take from him matzah on the day before Passover.”
I.F.
Yirmiyahu Katz
(Boyaner Hasid)