Hebrews 4:11-13
These things indeed (he would say) are sufficient to instruct us. But we have also “a great High Priest, that is passed into the heavens, Jesus the Son of God.” Because he added [it], for this reason he went on, “For we have not an High Priest who cannot be touched with the feeling of our infirmities.” Therefore he said above, “In that He has suffered Himself being tempted, He is able to succor them which are tempted.” See then how here also he does the same. And what he says is to this effect: He went (he says) the road which we also [are going] now, or rather even a more rugged one. For He had experience of all human [sufferings].
Source: Homilies on the Epistle to the Hebrews (New Advent)