R. Johanan b. Elazar had a tree which was overhanging another man's field. A man came before him with a similar case for judgment. He asked him to come on the morrow; meanwhile he cut down his own tree and advised the other man to do likewise.
The Rabbi Who Cut Down His Own Tree Before Judging the Case
Gaster, Exempla No. 154 (Bava Batra 60a)