Why is the article lām clear in «الْبَيْتِ»?

Al-Fīl and Quraysh: Applied Iẓhār, Ikhfāʾ, Idghām, Madd and Waqf

• Bāʾ is a moon letter
• Bāʾ is a sun letter
• There is tanwīn
• It triggers nūn assimilation