Pseudo-Augustine — as excerpted in the Catena Aurea on Mark 1:2-3

“(Quæst. nov. et vet. Test. lvii.) For knowing that all things are to be referred to their author, he has brought these sayings back to Isaiah, who was the first to intimate the sense. Lastly, after the words of Malachi, he immediately subjoins, The voice of one crying in the wilderness, in order to connect the words of each prophet, belonging as they do to one meaning, under the person of the elder prophet.”