Ka'bah as center of worship

إِنَّ أَوَّلَ بَيْتٍ وُضِعَ لِلنَّاسِ لَلَّذِى بِبَكَّةَ مُبَارَكًا وَهُدًى لِّلْعَـٰلَمِينَ

Indeed, the first House [of worship] established for mankind was that at Bakkah [i.e., Makkah] - blessed and a guidance for the worlds.