John Gill Commentary Luke 11:37

"Now as he spake, a Pharisee asketh him to dine with him: and he went in, and sat down to meat." — Luke 11:37 (ASV)

And as he spoke
Either the above words, or others at another time:

a certain Pharisee asked him to dine with him :
as one of the same sect had before, in (Luke 7:36) and who either was better affected to Christ than the generality of them were; or had a design upon him to get him into company with others, in private, and ensnare him if they could, and overcome him, who was an overmatch for them before the people; among whom they feared, should they go on thus publicly to attack him, their credit and reputation would sink, and be lost.

And he went in and sat down to meat :
whatever were the intentions of the Pharisee, Christ, who was always affable and free with all sorts of men, readily accepted of the invitation, and at once went along with him to his house; and dinner being ready, and on the table, he immediately sat down without any ceremony.