Gregory the Great
Catena Aurea · Lukasevangelium 10
After these things the Lord appointed other seventy also, and sent them two and two before his face into every city and place, whither he himself would come. Therefore said he unto them, The harvest truly is great, but the labourers are few: pray ye therefore the Lord of the harvest, that he would send forth labourers into his harvest. It follows, And he sent them two and two.
(ubi sup.) It is rightly added, before his face into every city and place, whither he himself would come. For the Lord follows His preachers, since the preaching comes first, and then the Lord enters into the tabernacle of our heart; seeing that through the words of exhortation going before, truth is received into the mind. Hence Esaias says to the preachers, Prepare ye the way of the Lord, make straight a highway for our God. (Isa. 40:3.)