Jamieson, Fausset and Brown on Luke 19:5-6

5-6. looked up,--in the full knowledge of who was in the tree, and preparatory to addressing him.

Zaccheus--whom he had never seen in the flesh, nor probably heard of. "He calleth His own sheep by name and leadeth them out" (Joh 10:3).

make haste, and come down--to which he literally responded--"he made haste and came down."

for to-day, &c.--Our Lord invites Himself, and in "royal" style, which waits not for invitations, but as the honor is done to the subject, not the sovereign, announces the purpose of royalty to partake of the subject's hospitalities. Manifestly our Lord speaks as knowing how the privilege would be appreciated.

to-day ... abide--(Compare Joh 1:39), probably over night.