קְלָעִ֛ים חֲמֵשׁ־עֶשְׂרֵ֥ה אַמָּ֖ה אֶל־הַכָּתֵ֑ף עַמּוּדֵיהֶ֣ם שְׁלֹשָׁ֔ה וְאַדְנֵיהֶ֖ם שְׁלֹשָֽׁה׃
The hangings for the one side [of the gate] were fifteen cubits; their pillars three, and their sockets three.
Read kabbalistic (mystical) interpretation of Exodus 38:14: and classical mystical sources.