Idra Raba: Chapter 34
The second and third of the nine Corrections (formations) of the beard of Zeir Anpin

Rabbi Aba describes the second Correction (formation) as meaning several things: it is like a dominating, great, beautiful and mighty man; it is mercy; it is truth. He talks a good deal about Chesed in various contexts; we learn that the third Correction (formation) is "and abundant in Chesed."