In the Ba'eir Heiteiv (באר היטב) commentary to the Shulchan Aruch, Orach Chaim 1, at the end of s'if katan 13, we find the words:
וכן העתיק הבאר היטב אשר לפני ע״ש ולא ידעתי למה.
And likewise, the Ba'eir Heiteiv that is in front of me brought/wrote [this idea], see there; and I do not know why.
Is this indeed a self-citation, and if so, why are his own words incomprehensible to him?