Rashi on Exodus 26:3/רש"י על שמות כ״ו:ג׳

1תהיין חברת SHALL JOIN TOGETHER — They sewed them together with a needle, each five separately.

2אשה אל אחתה ONE TO ANOTHER (lit., a woman to her sister) — This is the idiom of Biblical Hebrew — to speak thus about a thing that is of the feminine gender when it correlates it with a thing of the same kind. In the case of a thing that is masculine it uses the expression איש אל אחיו, lit., a man to his brother, as it is said, e. g. of the cherubim (Exodus 25:20) “and their faces were turned איש אל אחיו‎”.