Adam Clarke on Luke 18:14

Went down to his house justified - His sin blotted out; and himself accepted.

Rather than the other - Η εκεινος: that is, the other was not accepted, because he exalted himself - he made use of the mercies which he acknowledged he owed to God, to make claims on the Divine approbation, and to monopolize the salvation of the Most High! He was abased, because he vainly trusted that he was righteous, and depended on what he had been enabled to do, and looked not for a change of heart, nor for reconciliation to God. It is a strange perversion of the human mind, to attempt to make God our debtor by the very blessings which his mere mercy has conferred upon us! It was a maxim among the Jews, that whoever brought a sacrifice to the temple returned justified. But our Lord shows that this depended on the state of mind - if they were not humbled under a sense of sin, they were not justified, though they had even offered a sacrifice.