The Great Commentary of Cornelius à Lapide
Matthew 20:21
And He said unto her, &c. Christ wisely refuses the general petition, and would have her express it particularly, lest she should be asking for something foolish and unworthy, which He foresaw she would do, in order that He might teach us to do like He did.
She said to Him, &c. S. Chrysostom says, "They wished, since they had heard that the disciples should sit upon twelve thrones, to obtain the primacy of that seat, and they knew that they would be preferred before the rest with the exception of Peter; but fearing that Peter was preferred before them, they dared to say, 'Grant that one of us may sit on Thy right hand and the other on Thy left.'" We may learn from this how bold and blind and insatiable ambition is to which she incited these two Apostles, because they had seen that in the Transfiguration which was the beginning of Christ's kingdom they were preferred by Christ to the other Apostles.
But the mother is to be excused because she makes her request of Christ, her kinsman according to the flesh, for her sons whom she loved, even more than herself. So S. Jerome says, "The mother asks this from womanly error, and affectionate piety, not knowing what she was asking."
In the same way or manner S. Chrysostom excuses her sons. "Let not any one," he says, "be disturbed at our saying that the Apostles were so imperfect, for the mystery of the Cross had not yet been consummated; the grace of the Spirit had not yet been infused into their hearts. Wherefore if you wish to learn what their virtues were, consider what they were after the Spirit had been given, and you will see that all restlessness of mind was removed from them. For this reason only their imperfection is made known that you may perceive clearly what they were suddenly made by grace."
Ye know not what ye ask. Because ye know not, in the first place, of what sort My kingdom is namely, a spiritual and heavenly one, not a carnal and an earthly one. Secondly, because ye are asking for the triumph before the victory; "for the kingdom of Heaven suffereth violence, and the violent take it by force." Thirdly, because you suppose that this kingdom is given by right of blood to those who seek it, whereas it is given only to those who deserve and strive. Let bishops and princes, then, follow this example of Christ, and make answer to their friends, their sons, and to importunate women, when they ask them for prebends, dignities, and appointments for which they are unfitted, "Ye know not what ye ask." My prebends and appointments are not mine to give as I please, and because I so choose, to my relations and servants; I am a steward, not an owner; God will require an exact account of my stewardship. For great is the injury to Christ and His Church, and it is the cause of many evils, if appointments and benefices are given on account of relationship and friendship, to unworthy persons.
Ye know not what ye ask. First, because ye think that My kingdom is an earthly one, and one of outward show, like that of David and Solomon; whereas it is spiritual and heavenly. So S. Chrysostom says: "He says this to show that they were seeking nothing spiritual." Secondly, because they were asking for what had already been promised namely, to sit with Christ, and with Him to judge the twelve tribes of Israel. So S. Hilary: "They know not what they ask, because there was no doubt about the glory of the Apostles, for His former discourse had made it clear to them that they should judge the world." But among these thrones they seemed to have asked for the first, and the next to Christ, though they had not yet been specially promised by Christ to them. Thirdly, because they were asking for what exceeded the measure of their gifts and merits. Bede says: "They know not what they ask when they ask for a throne of glory which they had not yet merited." For the first thrones in Heaven belong to those who are of greater yea, of the greatest-merit. Fourthly, because they were asking at an unsuitable time, when the Passion of Christ was at hand. As S. Chrysostom says: "Ye speak of honour, but I speak of labours and toil; for this is no time for rewards, but rather for slaughter, battles, and perils." Fifthly, because they were asking for what was contrary to their vocation; for they were called to follow Christ in His poverty and cross, not to strive after honours. Sixthly, because they ought to have sought for the labours of the cross, by which they might merit honours. Seventhly, because they asked to sit on the left hand as well as on the right. For those condemned in the judgment will stand on Christ's left hand; which is, says S. Chrysostom, as it were to say, "I have called you to My right hand, and you wilfully are hastening from My right hand to My left." But this is a mystical meaning; the most suitable meanings are the first, the third, and the sixth.
Are ye able, &c. Through the Cross and Passion the way lies for Me to My kingdom, therefore the same way might be trodden by you if you desire it. S. Bernard says, that "Christ like a good and wise physician first drank the draught Himself which He was preparing for His own, i.e., He underwent His Passion and Death, and so He became immortal and impassible; thus teaching His own how they might confidently drink the draught which produces soundness and life." S. Chrysostom and Theophylact say that Christ called His Passion a cup, because He so willingly endured, and, as it were, drained it, as a thirsty man would a cup of wine. In Scripture, and among profane writers, the cup signifies the lot, whether good or evil, which God appoints, and as it were administers to each man.
S. Cyprian, understanding martyrdom by the cup, says, "A fiercer conflict is now at hand (for God had revealed to him that the Valerian persecution was coming), for which the soldiers of Christ ought to prepare themselves with firm courage, considering that for that very reason they daily drink the cup of the blood of Christ, so that they may also themselves be able to shed their blood for the sake of Christ." For at that time they used to communicate daily, and that under both kinds, bread and wine. S. Chrysostom remarks how "Christ encourages and draws them on by the way in which He puts the question. For He did not say, can ye shed your blood, but can ye drink the cup? Then, drawing them on, He says, which I shall drink of, so that by sharing with Him in His labours they may be rendered more ready to undergo the same."
Christ also calls His Passion a baptism, because in it He was wholly immersed and plunged, i.e., He died.
They say, We are able. John and James seem to have understood the meaning of the cup; and yet as they had shown their ambition in asking for the primacy, so they rashly answer, that they can drink the cup, whereas, in truth, they could not yet do so; but afterwards they were able, through the grace of Christ given by the Holy Ghost on the Day of Pentecost.