If Lǚ has appeared in your reading, the book is naming the condition of being between homes — literally on a journey, or figuratively passing through a season in which the usual supports of place, role, and standing are not available. Fire on the mountain: a light that moves, that does not settle, that warms briefly the ground it touches before passing on.

Classical commentary reads this hexagram as the discipline of life without home base. The wanderer cannot afford the luxuries of permanence: they cannot accumulate grudges, they cannot leave matters unresolved, they cannot impose on their hosts. The hexagram appears when the reader is in such a position — a transitional season, a long trip, a period of dependence on the hospitality of others — and the question is how to conduct oneself well inside it.

What the book counsels is the modesty that travel requires. 小亨 — small flowing — is exact. The big moves do not work in this season; the small ones do. Be polite. Carry little. Settle matters as they arise. Be kind to your hosts and do not overstay. The clearance — auspicious — is for the wanderer who does these things, and not for the one who travels as if their old standing still applied.

Lǚ's failure mode is the importation of one's home behaviour into the road. The book is alert to it. The hexagram appears when the reader is in a setting where they have less standing than they are accustomed to, and the temptation is to act as if the standing has come with them. It has not. The work is to recognise the new register and to operate cleanly inside it. The journey will end; some other hexagram will return; the conduct of the road will be remembered by those who hosted it.