John Lightfoot on Luke 19:9

[This day is salvation come to this house.] It is said, verse 7, "That they all murmured that Christ was gone to be guest with a man that is a sinner." What then did they think of the house itself that belonged to this sinner? Do we think they would enter in, when they despised any thing that belonged to publicans? Perhaps that expression Zacchaeus stood and said, may seem to hint that he came forth, and stood talking with those that were without doors, and would not enter. However, if we well consider how meanly they accounted of the house of a publican, we may the more easily understand what the meaning of that expression is, This day is salvation come to this house.

[Forasmuch as he also is a son of Abraham.] That is, say most, the son of Abraham by faith; which indeed is most true. But I doubt, however, that this is not directly the sense of these words. For I question whether the Jews knew of any kind of relation to Abraham but that which was according to the flesh, and by way of stock and offspring. The son of Abraham by faith was a notion unknown; and I scarce believe our Saviour would speak to them in an unintelligible dialect...