Mark 1:7

‘And he preached, saying, “There comes after me he who is mightier than I, the fastening of whose shoes I am not worthy to stoop down and unloose”.'

The unfastening of sandals was work regularly a task performed by servants and foreign slaves. Those who entered a house were relieved of the dust or mud of the streets by servants, who would take off their sandals, and regularly also wash their feet. In Palestine a Hebrew slave was exonerated from this humiliating task, and Rabbi Joshua b. Levi is quoted as saying, ‘All services which a slave does for his master a pupil should do for his teacher, with the exception of undoing his shoes.' So by his words John declares that compared with the Coming One he is lower than the lowest servant or even a Gentile slave. He is as nothing before Him, not even fit to perform that lowliest and most despised of tasks, the unfastening of His shoes.

‘He Who is mightier than I.' The word indicates strength and power. In the original prophecy the way was being prepared for YHWH, Who would pour out His Spirit on His people (Isaiah 44:1), although the activity of the hoped for Davidic King (Isaiah 9:6; Isaiah 11:1; Isaiah 55:3) may also have been in mind. But here the mightier One is clearly Jesus Christ, the Son of God. It is as ‘the mighty one', the ‘mightier than he', that Jesus overcomes Satan and his minions (Mark 3:27 compare Luke 11:22). And it is with mighty power that He proclaims His message and heals the sick (Luke 4:14; Luke 4:32). It is a power that He is able to pass on to others on His own authority (Mark 3:15; Luke 9:1). But it may be that here John mainly has in mind the contrast between the baptism which he can himself administer, which is but a picture of what is to come, as compared with that which Jesus will administer, which will be the supreme ‘baptism', the ‘drenching in Holy Spirit', that which is the prerogative of God.