7 And these things we tell you, that you may not hear only, but imitate also his manly severity, his plainness of speech, his righteousness in all things; that no one may despair of himself, though hitherto he have been careless, that he may set his hopes on nothing else, after God's mercy, but on his own virtue. For if these were nothing the better for such a kindred, though they were of the same house and lineage with Christ, until they gave proof of virtue; what favor can we possibly receive, when we plead righteous kinsmen and brethren, unless we be exceeding dutiful, and have lived in virtue? As the prophet too said, intimating the selfsame thing, “A brother redeems not, shall a man redeem?” No, not although it were Moses, Samuel, Jeremiah. Hear, for example, what God says unto this last, “Pray not thou for this people, for I will not hear you.” And why do you marvel if I hear not you? “Though Moses himself and Samuel stood before me,” I would not receive their supplication for these men. Yea, if it be Ezekiel who entreats, he will be told, “Though Noah stand forth, and Job, and Daniel, they shall deliver neither sons nor daughters.” Though the patriarch Abraham be supplicating for them that are most incurably diseased, and change not, God will leave him and go His way, that he may not receive his cry in their behalf. Though again it be Samuel who is doing this, He says unto him, “Mourn not thou for Saul.” Though for his own sister one entreat, when it is not fitting, he again shall have the same sort of answer as Moses, “If her father had but spit in her face.”
Let us not then be looking open-mouthed towards others. For it is true, the prayers of the saints have the greatest power; on condition however of our repentance and amendment. Since even Moses, who had rescued his own brother and six hundred thousand men from the wrath that was then coming upon them from God, had no power to deliver his sister; and yet the sin was not equal; for whereas she had done despite but to Moses, in that other case it was plain impiety, what they ventured on. But this difficulty I leave for you; while that which is yet harder, I will try to explain.
For why should we speak of his sister? Since he who stood forth the advocate of so great a people had not power to prevail for himself, but after his countless toils, and sufferings, and his assiduity for forty years, was prohibited from setting foot on that land, touching which there had been so many declarations and promises. What then was the cause? To grant this favor would not be profitable, but would, on the contrary, bring with it much harm, and would be sure to prove a stumbling-block to many of the Jews. For if when they were merely delivered from Egypt, they forsook God, and sought after Moses, and imputed all to him; had they seen him also lead them into the land of promise, to what extent of impiety might they not have been cast away? And for this reason also, let me add, neither was his tomb made known.
And Samuel again was not able to save Saul from the wrath from above, yet he oftentimes preserved the Israelites. And Jeremiah prevailed not for the Jews, but some one else he did haply cover from evil by his prophecy. And Daniel saved the barbarians from slaughter, but he did not deliver the Jews from their captivity.
And in the Gospels too we shall see both these events come to pass, not in the case of different persons, but of the same; and the same man now prevailing for himself and now given up. For he who owed the ten thousand talents, though he had delivered himself from the danger by entreaty, yet again he prevailed not, and another on the contrary, who had before thrown himself away, afterwards had power to help himself in the greatest degree. But who is this? He that devoured his Father's substance.
So that on the one hand, if we be careless, we shall not be able to obtain salvation, no not even by the help of others; if, on the other hand, we be watchful, we shall be able to do this by ourselves, and by ourselves rather than by others. Yes; for God is more willing to give His grace to us, than to others for us; that we by endeavoring ourselves to do away His wrath, may both enjoy confidence towards Him, and become better men. Thus He had pity on the Canaanitish woman, thus He saved the harlot, thus the thief, when there was none to be mediator nor advocate.
Source: Homilies on the Gospel of St. Matthew (New Advent)