«كُل وَاحِدْ يِنَامْ عَلَى الْجَنْبِ اللِّي يْرَيَّحُهْ»

The saying is figurative: it takes the private, ordinary choice of which side to lie on at night as an image for how people manage their own lives, not a remark about rest itself. No one tells another person how to settle into bed, and the same courtesy applies to wider personal decisions.

Its practical message is restraint toward others. When someone has worked out a plan or habit that gives them ease, bystanders are urged not to object or meddle, because the person who must live with that choice is the best judge of whether it truly suits them.

Use it when someone second-guesses how another person has arranged their own affairs, to defend that choice or explain why one will not interfere. It suits relaxed, everyday talk, but depending on tone it can also close a discussion or decline advice, and may sound dismissive.