Exegesis:
egō eimi (cf. 13.6) ‘I am’: it is probable that the words carry a meaning that goes beyond a simple affirmative answer to the question (cf. Translator’s New Testament ‘I am He’). As a set phrase (cf. their use in 13.6) the words carry an overtone of Messianic and divine self-identification.
opsesthe ‘you shall see’: this is addressed directly to the whole council as a statement of fact (in 13.26 opsontai is impersonal, ‘they shall see,’ i.e. ‘men shall see’). As in the parallel statement in 9.1 so here the verb ‘see’ should be translated unequivocally to indicate an actual experience on the part of those addressed.
ton huion tou anthrōpou ek dexiōn kathēmenon tēs dunameōs ‘the Son of man sitting at the right hand of the Power’: as in 13.36, the words are a reference to Ps. 110.1.
ho huios tou anthrōpou (cf. 2.10) ‘the Son of man.’
ek dexiōn (cf. 10.37; 12.36) ‘at the right (hand)’: as in both other passages, this is the place of authority and power.
hē dunamis (cf. 5.30) ‘the Power’: as in the case of ‘the Blessed One’ in the previous verse, this is a title for God.
erchomenon meta tōn nephelōn tou ouranou ‘coming with the clouds of heaven’: as in 13.26, these words are a reference to Dan. 7.13 (the Hebrew has ‘with the clouds of heaven’ while the Septuagint has ‘upon the clouds’; in 13.26 the expression is ‘in clouds’).
Translation:
Though the words I am may imply a subtle allusion to the divine self-revelation (cf. Exodus 3.14), it is difficult, if not impossible, to reproduce this type of allusion in a receptor language. In most languages Jesus’ reply must be either (1) an affirmative such as ‘yes’ or ‘that is right’ or (2) a declaration such as ‘I am the Christ.’ In most instances it is quite impossible to translate literally ‘I am’ because the copulative verb requires some type of so-called predicate complement.
As in other instances of the use of the Son of man in this first person relationship, it may be necessary to say ‘me who am the ‘Son of man’ or ‘me as the Son of man.’
Power cannot be used as a substitute for God in some languages since not only is the figure ‘right hand of the Power’ unintelligible, but ‘power’ does not exist apart from a possessor, e.g. ‘God who has power’ (Tzeltal) or ‘the one who has power’ (Central Mazahua).
Where there are two processes (namely, ‘sitting’ and ‘coming’) as objects of the verb ‘see,’ it may be necessary to repeat the verb in order to avoid the implication that the Son of man comes in a seated position. Hence, the rendering may be ‘see the Son of man; he will be sitting at the right hand of God who has power. And you will see him coming….’
With the clouds of heaven implies the position of the Son of man, not the fact that he will be coming, having in his possession the clouds of heaven. Moreover, one must not render with in merely the sense of accompaniment, i.e. that Jesus will be accompanying the clouds of heaven. In many instances ‘in’ is a more correct translation of the Greek meta than a presumably more literal rendering which may, however, have quite different denotations in such a context.
Quoted with permission from Bratcher, Robert G. and Nida, Eugene A. A Handbook on the Gospel of Mark. (UBS Handbook Series). New York: UBS, 1961. For this and other handbooks for translators see here .