Mark 6:31

(in Marc. 2, 25) Leaving also Judæa, the holy preachers, in the desert of the Church, overwhelmed by the burden of their tribulations amongst the Jews, obtained rest by the imparting of the grace of faith to the Gentiles.

And he said to them: Come apart into a desert place, and rest a little while, etc. Not only for the sake of their rest, but also for the mystical significance, because indeed Judah, having abandoned, which had taken away the head of prophecy from itself by not believing, in the desert of the Church which had no husband, the food of the word would be for the believers, as if to bestow feasts of bread and fish. For there the holy preachers, who in unbelieving and opposing Judea, were for some time pressed by the heavy burden of tribulations, found rest from the grace of faith bestowed upon the nations. And what need there was to grant rest to the disciples is subsequently shown, when it says:

For many were coming and going, and they had not even time to eat. Where the great happiness of that time is demonstrated by the labor of the teachers and the zeal of the learners, which would that it return in our time, so that such great crowds of faithful listeners throng to the ministers of the word, that they have no free time for tending to the body. For when the necessary hour for tending to the body is denied, how much less is there opportunity for indulging in the allurements of soul or flesh? Rather, from whom the word of faith and the ministry of salvation is sought timely and untimely, the spirit of these men is consequently kindled always to do and think of heavenly things, lest by their actions they contradict what they teach with words.