Albert Barnes Commentary Mark 1:2

"Even as it is written in Isaiah the prophet, Behold, I send my messenger before thy face, Who shall prepare thy way." — Mark 1:2 (ASV)

Verses 2 and 3: As it is written in the prophets. He mentions prophets, here, without specifying which. The passages are found in Malachi 3:1; and in Isaiah 40:3.