When you see a friend who is going to travel, you'd say:
What would you say to someone who has arrived from a quite long and exhausting trip?
This answer is based on the assumption that Gigili looks for something to say to someone who has had a long rather exhausting voyage. Having completed such voyage would merit the person something like this:
Of course there is more to say... things like:
But this is but stuff to say in situations. Nothing particularly German about it. Let your fantasy soar to get more ;)
There are lots of possibilities and they depend on how good you know that person (using "Du" or "Sie" for example). Some examples:
You also can combine them:
Personally, I would not ask immediately about the trip, but ask about whether the visitor wants to sit down/drink/maybe even use the shower.
While the visitor rests and drinks, I will then ask about the trip.
Wenn ich jemanden begrüßen kann, klappt's mit dem "Willkommen" fast immer. Wenn's das Ende einer Reise ist, sollte man wieder zu Hause sein:
Dann würde ich mal an das Dringenste denken:
Edit: Der Imparativ kann mit oder ohne -e geschrieben werden. Ein Auslassungszeichen (Apostroph) ist nicht erforderlich.