Augustine of Hippo — as excerpted in the Catena Aurea on Mark 14:32-42

“(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 shews 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 shews, 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 shew 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.”