Kimi ga yo wa kagiri mo araji nagahama no masago no kazu wa yomitsukusu tomo - Kokin Wakashu(English Translation & Meaning)

君が代は限りもあらじ長浜の
真砂の数は読みつくすとも

Roma-ji: Kimi ga yo wa kagiri mo araji nagahama no masago no kazu wa yomitsukusu tomo
English Translation: Your reign, my lord,
will surely know no ending,
though on Nagahama
all the grains of fine sand
were counted to the last.
Meaning: Your reign, my lord, will have no end, even if every grain of sand on Nagahama beach were counted out.
Commentary: Book Twenty Poems of the Bureau of Court Song 1085

Headnote: "Kagura Songs: Kaeshimono Song"
Even if the countless grains of sand on the long beach could be counted to the last, the singer says, the lord's reign will have no end. Raising something beyond count and then surpassing it is a typical move of the congratulatory poem. No author is recorded.
Kaeshimono songs are thought to be songs sung in a changed musical mode within the kagura. They run from poem 1081 to 1086, and from 1082 onward each of the five carries a left-hand note saying it was presented by a province at a Great Thanksgiving Festival (daijōe).
The left-hand note says, "This is the song of the province of Ise at the daijōe of Ninna," the Great Thanksgiving of Emperor Kōkō, for which Ise presented it. The daijōe was the first harvest festival held by a newly enthroned emperor, and the provinces chosen as Yuki and Suki presented songs that named places in their own lands.

The first line, "your reign, my lord," names what the blessing is for.
The second line, "will surely know no end," uses ji, negative conjecture. The poem breaks here, stating its conclusion first.
The third line, "of Nagahama," names a beach in Ise, placing the offering province's land in the song.
The fourth line, "the number of its sands," is a figure for the uncountable.
The last line, "though one count them to the end," uses yomu in the sense of counting and tomo for a concessive supposition. Inverted with the second line, it stresses boundless length.
Source: Kokin Wakashu
Prev Poem: Mino no kuni seki no fujikawa taezu shite kimi ni tsukaemu yorozuyo made ni
Next Poem: Ōmi no ya kagami no yama o tatetareba kanete zo miyuru kimi ga chitose wa