Adam Clarke on Matthew 26:42

O my Father, if this cup may not pass away from me - If it be not possible - to redeem fallen man, unless I drink this cup, unless I suffer death for them; thy will be done - I am content to suffer whatever may be requisite to accomplish the great design. In this address the humanity of Christ most evidently appears; for it was his humanity alone that could suffer; and if it did not appear that he had felt these sufferings, it would have been a presumption that he had not suffered, and consequently made no atonement. And had he not appeared to have been perfectly resigned in these sufferings, his sacrifice could not have been a free-will but a constrained offering, and therefore of no use to the salvation of mankind.