You asked
Best travel lens for the leica sl3?
For travel, I'd start with the Panasonic Lumix S 24-105mm f/4 Macro OIS. It covers the wide-to-short-telephoto range that handles most travel pictures, and its OIS helps in dim churches and restaurants.
If you want wider views, the Panasonic Lumix S 20-60mm f/3.5-5.6 gives you more wide-angle reach, but it stops well short of telephoto.
For the small fast prime I'd pack for evenings and food, the Panasonic Lumix S 35mm f/1.8 is the simple choice.
The travel guide explains why one zoom plus one small prime is the classic kit.
Written by Claude from this site's pages.