**** comprises two elements, **** \+ the particle ****.
> * is the {}{}{} of the {}{}{} verb {}, which is the classical equivalent of the modern Japanese verb {}.
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> * When the particle is combined with the , it means "because/since" or "when/as."
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> In this case, it's the "when/as" meaning of that suits the context, so we can translate as " **when I look out** " or " **as I gaze out** ," etc.
**** is a group of like things, animals, or people arranged in a line or row.
> * Sometimes this word is rendered in kanji as , , or .
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> * The two elements comprises aren't actually + , as the wording of your question implies, but + , where means "one" and means "line" or "row." (cf. the modern verbs {} and {}.)
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> In the poem, **** refers to a **skein of wild geese** flying in the sky.
You can read a bit about the usage of in classical Japanese here. Note that has a very different meaning when combined with the {}{}{} instead of the .)