Mark 10:38

‘But Jesus said to them, “You do not know what you ask. Are you able to drink the cup that I drink? Or to be baptised with the baptism that I am baptised with?”

Jesus' reply was veiled, and yet open to those who would see it and who had listened to all His warnings of what was to come. The king's cup was drunk by his favourites and both Jesus and His disciples had been baptised by John. This was probably what his statement initially meant to the disciples. They felt well able to fit in with the requirements. Yes, they would say confidently, we can do both.

‘You do not know what you are asking.' Jesus warned them to appreciate that they might be asking more than they realised. To take their position by His side meant being involved in what He was going to be involved in. Were they prepared for that? Did they even know what it was? (Did they, for example, want to be on each side of Him when He was on the cross, as Mark will later point out that the insurrectionists were (Mark 15:27)?) They little realised how they must have been grieving Jesus at their lack of understanding.

‘Are you able to drink the cup that I am drinking?' With His eyes ahead on the sorrows that awaited Him He had already begun to drink the cup, and He knew that He would have to drink it to the full. The cup was the cup of suffering (Mark 14:34; Mark 14:36) and the cup of God's wrath, regularly mentioned in the Old Testament, to be drunk by the One Who was made sin for us. ‘In the hand of the Lord there is a cup and the wine is red' and it is for all the wicked of the earth (Psalms 75:8). Jerusalem had ‘drunk at the hand of the Lord the cup of His fury' (Isaiah 51:17). ‘Take the cup of the wine of this fury at my hand and cause all the nations, to whom I send you, to drink it' (Jeremiah 25:15 see also Jeremiah 49:12; Lamentations 4:21; Ezekiel 23:31; Habakkuk 2:16; Psalms 60:3; Isaiah 63:6; Obadiah 1:16 compare Revelation 14:10). In the words of Job, ‘let him drink of the wrath of the Almighty' (Job 21:20).

‘Or to be baptised with the baptism I am being baptised with?' Jesus was here thinking of being overwhelmed with suffering (compare Luke 12:50). The word ‘baptizo' was used by the Greeks of overwhelming calamities. Isaiah 21:4 LXX renders ‘horror has frightened me' from the Hebrew into the Greek as, ‘lawlessness has baptised me' with the same idea of being overwhelmed. Aquila also in his Greek translation of the Old Testament translates Psalms 69:2 ‘the floods overflow me' by using baptizo. The idea of such overwhelming appears regularly in the Old Testament (Psalms 42:7 - ‘all your waves and your billows are gone over me'; see also Jonah 2:3; Psalms 69:15; Psalms 124:4; Isaiah 43:2). So Jesus was thinking of being overwhelmed by suffering, including, in the light of the cup, the horror of the wrath of God which He would bear for us (Mark 10:45).