Rarely would the Messenger of Allah ﷺ set out on a journey except on a Thursday.
لقلما كان رسول الله ﷺ يخرج، إذا خرج في سفر إلا يوم الخميس.
Bukhari narrated it in the Book of Jihad and Expeditions (2949), saying, and from Yunus, from Zuhri, who said, Abdul-Rahman bin Kaab bin Malik told me that Kaab bin Malik used to say... and he mentioned it. This is connected to the chain before it (2948), Ahmad bin Muhammad narrated to us, Abdullah told us, Yunus told us, from Zuhri with the aforementioned chain.