Comprehension, language, and application

What limit is expressed by «حَتَّى تَخْتَلِطُوا بِالنَّاسِ»?

Moral Awareness, Social Etiquette, and Conditional Sentences with Idhā (Hadith 253–266)

• Once among others, that particular three-person situation changes
• Always isolate the third
• Whispering is forbidden only until food starts
• Every conversation between two is forbidden