וַיְהִ֨י לִשְׁלֹמֹ֜ה אַרְבַּעַת֩ אֲלָפִ֨ים אֻֽרְי֤וֹת סוּסִים֙ וּמַרְכָּב֔וֹת וּשְׁנֵים־עָשָׂ֥ר אֶ֖לֶף פָּרָשִׁ֑ים וַיַּנִּיחֵם֙ בְּעָרֵ֣י הָרֶ֔כֶב וְעִם־הַמֶּ֖לֶךְ בִּירוּשָׁלִָֽם׃
And Solomon had four thousand stalls for horses and chariots, and twelve thousand horsemen, that he bestowed in the chariot cities, and with the king at Jerusalem.
Rashi
Forty thousand stables of horses. In Divrei Hayomim it states, “four thousand [stables of horses].”2II Divrei Hayomim 9:25. Our Rabbis explained there were forty thousand stables and in each there were four thousand partitions, or there were four thousand stables and in each there were forty thousand partitions.3See Maseches Sanhedrin 21b.