Sentence:  Francis is of the race of mystics, for no intermediary comes between God and his soul; but his mysticism is that of Jesus leading his disciples to the Tabor of contemplation; but when, <WSD>overflooded</WSD> with joy, they long to build tabernacles that they may remain on the heights and satiate themselves with the raptures of ecstasy, "Fools," he says to them, "ye know not what ye ask," and directing their gaze to the crowds wandering like sheep having no shepherd, he leads them back to the plain, to the midst of those who moan, who suffer, who blaspheme. 
Meaning of the word marked with <WSD> tags:  To flood or fill completely; to overflow.