Reading a source in kuzushiji 2 – introduction

行川のながれは絶ずして、しかも本の水にあらず。
よどみにうかぶうたかたは、かつ消かつ結びて久敷とどまることなし。

As an alternative to writing the same syllable with a different hiragana and, mainly, in the case of the same character being repeated consecutively, it is common in Japanese texts to use odoriji (踊字), ideographic iteration marks used instead of repeating a preceding kana or kanji (ゝfor kana and〻or 々 for kanji).
Due to their graphic simplicity, odoriji are often challenging to spot and recognize in old Japanese texts, as they can easily be mistaken for strokes of neighbouring characters.