From: Swampland Flowers: The Letters and Lectures of Zen Master Ta Hui (1088-1163); Tr. Christopher Cleary:
As gentlemen of affairs, your study of the Path differs greatly from mine as a homeleaver. Leavers of home do not serve their parents and abandon all their relatives for good. With one jug and one bowl, in daily activities according to circumstances, there are not so many enemies to obstruct the Path. With one mind and one intent (homeleavers) just investigate this affair thoroughly. But when a gentleman of affairs opens his eyes and is mindful of what he sees, there is nothing that is not an enemy spirit blocking the Path. If he has wisdom, he makes his meditational effort right there. As Vimalakirti said, "The companions of passion are the progenitors of the Tathagatas: I fear that people will destroy the worldly aspect to seek the real aspect." He also made a comparison: "It's like the high plateau not producing lotus flowers; it is the mud of the lowlying marshlands that produces these flowers."
If you can penetrate through right here, as those three elders Yang Wen-kung, Li Wen-ho and Chan Wu-chin did, your power will surpass that of us leavers of home by twentyfold. What's the reason? We leavers of home are on the outside breaking in; gentlemen of affairs are on the inside breaking out. The power of one on the outside breaking in is weak; the power of one on the inside breaking out is strong. "Strong" means that what is opposed is heavy, so in overturning it there is power. "Weak" means that what is opposed is light, so in overturning it there is little power. Though there is strong and weak in terms of power, what is opposed is the same.