Just as rain breaks through an ill-thatched house, so passion penetrates an undeveloped mind.

A domestic image. The thatched house — the standard rural dwelling of the Buddha's era, still the standard in much of the world today — is the body, or perhaps the life, into which one has not yet brought the work. The rain is passion. The teaching is not that passion is wrong. It is that passion entering an unprepared structure does damage, and the damage is structural. The Buddha is recommending the work of thatching before the season turns.