8 This is the active participle, not the passive. It would normally be rendered “joining together.” The Bible uses the active because it has the result of the sewing in mind, namely, that every curtain accompanies another (U. Cassuto, Exodus, ).
9 Heb “a woman to her sister,” this form of using nouns to express “one to another” is selected because “curtains” is a feminine noun (see §139.e).
10 The phrase “the other” has been supplied.

In other versions

Five curtains shall be coupled to one another, and the other five curtains shall be coupled to one another.

Join five of the curtains together, and do the same with the other five.

Five of the curtains should be joined together, and the other five curtains joined together.

Join five of these curtains together to make one long curtain, then join the other five into a second long curtain.

Five curtains will be joined to one another, and five curtains joined to one another.

The five curtains shall be coupled together one to another; and other five curtains shall be coupled one to another.

Public Domain