The publican, standing afar off - Not because he was a heathen, and dared not approach the holy place; (for it is likely he was a Jew); but because he was a true penitent, and felt himself utterly unworthy to appear before God.
Would not lift up - his eyes - Holding down the head, with the eyes fixed upon the earth, was, A sign of deep distress.
Of a consciousness and confession of guilt. And,
It was the very posture that the Jewish rabbins required in those who prayed to God.
See Ezra 9:6; and Mishna, in Berachoth, chap. v.; and Kypke's note here. So the Pharisee appears to have forgotten one of his own precepts.
But smote upon his breast - Smiting the breast was a token of excessive grief, commonly practised in all nations. It seems to intimate a desire, in the penitent, to punish that heart through the evil propensities of which the sin deplored had been committed. It is still used among the Roman Catholics in their general confessions.
God be merciful to me - Ἱλασθητι μοι - Be propitious toward me through sacrifice - or, let an atonement be made for me. I am a sinner, and cannot be saved but in this way. The Greek word ἱλασκω, or ἱλασκομαι, often signifies to make expiation for sin; and is used by the Septuagint, Psalms 65:4; Psalms 78:38; Psalms 79:9, for כפר kipper, he made an atonement. So ἱλασμος a propitiation, is used by the same, for חטאה chataah, a sacrifice for sin, Ezekiel 44:27; and ἱλαστηριον, the mercy seat, is, in the above version, the translation of כפרת kapporeth, the lid of the ark of the covenant, on and before which the blood of the expiatory victim was sprinkled, on the great day of atonement. The verb is used in exactly the same sense by the best Greek writers. The following from Herodotus, lib. i. p. 19, edit. Gale, is full in point. Θυσιῃσι μεγαλῃσι τον εν Δελφοισι θεον ἹΛΑΣΚΕΤΟ, Croesus appeased, or made an atonement to, the Delphic god by immense sacrifices. We see then, at once, the reason why our blessed Lord said that the tax-gatherer went down to his house justified rather than the other: - he sought for mercy through an atonement for sin, which was the only way in which God had from the beginning purposed to save sinners. As the Pharisee depended on his doing no harm, and observing the ordinances of religion for his acceptance with God, according to the economy of grace and justice, he must be rejected: for as all had sinned and come short of the glory of God, and no man could make an atonement for his sins, so he who did not take refuge in that which God's mercy had provided must be excluded from the kingdom of heaven. This was no new doctrine: it was the doctrine publicly and solemnly preached by every sacrifice offered under the Jewish law. Without shedding of blood there is no remission, was the loud and constant cry of the whole Mosaic economy. From this we may see what it is to have a righteousness superior to that of the scribes and Pharisees. We must humble ourselves before God, which they did not: we must take refuge in the blood of the cross, which they would not; and be meek and humble of heart, which they were not.
Many suppose that the Pharisees thought they could acquire righteousness of themselves, independently of God, and that they did not depend on him for grace or power: but let us not make them worse than they were - for this is disclaimed by the Pharisee in the text, who attributes all the good he had to God: O God, I thank thee, that I am not as others - it is thou who hast made me to differ. But this was not sufficient: restraining grace must not be put in the place of the great atonement. Guilt he had contracted - and this guilt must be blotted out; and that there was no way of doing this, but through an atonement, the whole Jewish law declared. See the note on Matthew 5:20.