Charles Ellicott Commentary 1 Chronicles 6:67

"And they gave unto them the cities of refuge, Shechem in the hill-country of Ephraim with its suburbs; Gezer also with its suburbs," — 1 Chronicles 6:67 (ASV)

And they gave unto them, of the cities of refuge ... —The correct version of the Hebrew text is, And they gave to them the cities of refuge, Shechem and her pastures, in the hill-country of Ephraim; and Gezer and her pastures. Perhaps both here and in 1 Chronicles 6:57 above “city” (‘iyr), and not “cities” (‘arey), is the original reading. We have already noticed many indications of textual corruption in this and the former section. Gezer was not a city of refuge. (See Note on 1 Chronicles 6:57.)Joshua 21:21 has the singular.