classic waka stream

If the dark comes on
before I reach a lodging
and I take instead
the shade beneath a tree, then
the blossoms host me tonight

Meaning
If the dark comes on before I reach a lodging, and I take the shade beneath a tree instead, then the blossoms are my host tonight.
Commentary
Volume Nine: The Death of Tadanori

　The Taira were beaten at Ichi-no-tani, and Tadanori too rode west. Okabe Rokuyata Tadazumi of Musashi overtook him and called out that it was cowardly to show one's back to the enemy. Tadanori glanced around and said he was on their own side and that Rokuyata was mistaken—and as he spoke, his blackened teeth showed. No man on the Minamoto side blackens his teeth, said Rokuyata; come on—and he brought his horse alongside and grappled.
　The hundred or so men around Tadanori made no move to help; they shouted and scattered. They were a scratch force with no will to fight.
　Tadanori, raised in Kumano, was famously strong and quick besides. He seized Rokuyata, said it would have been better to let a man's word stand, struck twice from the saddle, threw him down and thrust once more—but the second blow would not go through the armor and the third was shallow, and as he moved to take the head, Rokuyata's retainer came up late and cut at him. Caught off guard, Tadanori lost his right arm at the shoulder. Resigning himself, he said he would chant the ten invocations and told them to stand back, threw Rokuyata off with the arm he had left, faced west and called out the words of the Buddha's all-embracing light—and before he finished, Rokuyata's blade came down and the head fell forward.
　He must have been a commander of some name, they said; but who? Untying a paper fastened to his quiver, they found a poem written out under the topic "blossoms at a traveler's lodging." This is it. From the name written there they knew him for the Governor of Satsuma.

　The topic is blossoms at a lodging on a journey. If darkness comes before one finds shelter and one passes the night under a tree, then that cherry is the host—a set topic joining travel and flowers.
　When it was written it was a peaceable poem. The moment it is tied to a quiver and read as the paper identifying a dead man, its sense turns over. The one overtaken by dark was Tadanori himself, fleeing west, and the shade beneath a tree became his actual last place. What happened to "the capital at Shiga" in Volume Seven happens to this man a second time: circumstance rewrites the poem.
　His first poem in the tale was in Volume Five, where he told the woman not to grieve because the barrier he would cross was one his forebears had crossed. He begins in the pride of following an ancestor's road and ends with no lodging at all, calling the blossoms his host. The tale remarks that not forgetting poetry even in death was very like him; and when Rokuyata announced the name, men on both sides wept for a commander distinguished in arms and in poetry alike.

yukikurete……overtaken by dark before arriving.
ki no shita kage……the shade beneath a tree.
yado to seba……if I make it my lodging.
aruji……the host, the master of a lodging.
naramashi……would it then be?
ryoshuku no hana……blossoms at a traveler's lodging; the topic set for the poem.
ebira……the quiver carried on the back.
kane……blackened teeth, a courtier's practice.
jūnen……ten invocations of Amida's name.
Okabe Rokuyata Tadazumi……a warrior of Musashi province.
Source
Heike Monogatari
Other