Romans 10:15

and how shall they preach, except they be sent? even as it is written, How beautiful are the feet of them that bring glad tidings of good things!

'except they be sent?' -'God has not only provided the Christ to obtain for us the ground of our righteousness; he has not only provided the revelation of that work of Christ, he has also provided the messengers to carry that blessed message..why whine and pout about missing the Messianic blessings when God is laboring so loving and so hard to bring those blessings to the unblessed?' (McGuiggan pp. 312,313)

'sent' -'Sending is the last step as we reason backward, but the first as we look forward toward salvation;...Paul argues back from effect to cause, so that, turning his series around, it will read, Sending, preaching, hearing, believing, turning to or calling upon God, salvation. (Acts 8:4)'

'even as it is written'. Isaiah 2:7

'How beautiful are the feet of them that bring glad tidings of good things' -'How pleasant is the coming of men with glad, good news!' (Mof)

'Passages like Nahum 1:15 and Isaiah 2:9 come to mind in this connection. In both of these places we have good news told by people standing on the mountains around Jerusalem and shouting to the people of the city that their enemies (Nineveh in Nahum and Babylon in Isaiah) have come in judgement. Isaiah 2:7 is the one Paul explicitly calls on. The feet that carry good news of God's delivering work are "beautiful". The deliverance from Babylon or the fierce Assyrian was good news but the deliverance that these "apostles" proclaim is deliverance from the very Devil himself.'

'Feet' -'covered with dust because of the long running, they are simply "beautiful" to the eyes of these longing captives because of the message they are bringing.' (Lenski p. 663)

We should note that: 'God does not act directly upon man in order to produce faith. He acts mediately, indirectly, through the word of faith which is "nigh" him.'

Even in the day and age of the miraculous, the 'message of salvation' was always brought by. another person. (Acts 8:26; Acts 9:6; Acts 9:17 (Romans 22:16); Romans 10:3-6; Romans 11:13-14)