Mark 14:36

(ubi sup.) But He prays, that the cup may pass away, to show that He is very man, wherefore He adds: Take away this cup from me. But remembering why He was sent, He accomplishes the dispensation for which He was sent, and cries out, But not what I will, but what thou wilt. As if He had said, If death can die, without my dying according to the flesh, let this cup pass away; but since this cannot be otherwise, not what I will, but what thou wilt. Many still are sad at the prospect of death, but let them keep their heart right, and avoid death as much as they can; but if they cannot, then let them say what the Lord said for us.

By which also He ceases not up to the end to teach us to obey our fathers, and to prefer their will to ours.

(de Con. iii. iv) He said not, if He could do it, but if it could be done; for whatever He wills is possible. We must therefore understand, if it be possible, as if it were; if He is willing. And lest any one should suppose that He lessened His Father's power, he shows in what sense the words are to be understood; for there follows, And he said, Abba, Father, all things are possible unto thee. By which He sufficiently shows, that the words, if it be possible, must be understood not of any impossibility, but of the will of His Father. As to what Mark relates, that he said not only Father, but Abba, Father, Abba is the Hebrew for Father. And perhaps the Lord said both words, on account of some Sacrament contained in them; wishing to show that He had taken upon Himself that 1sorrow in the person of His body, the Church, to which He was made the chief corner stone, and which came to Him, partly from the Hebrews, who are represented by the word Abba, partly from the Gentiles, to whom Father belongs.