John Cassian, Conferences XI–XVII XI.15: The postponement of the explanation which is asked for

Chæremon: It is indeed a sign of the utmost blessedness and of singular goodness both continually to learn and to teach that love by which we cling to the Lord, so that meditation on Him may, as the Psalmist says, occupy all the days and nights of our life, and may support our soul, which insatiably hungers and thirsts after righteousness, by continually chewing the cud of this heavenly food. But we must also, in accordance with the kindly forethought of our Saviour, make some provision for the food of the body, that we faint not by the way, for “the spirit indeed is willing, but the flesh is weak.” And this we must now secure by taking a little food, so that after supper, the mind may be rendered more attentive for the careful tracing out of what you want.