Exegesis:

hotan (cf. 11.19) ‘whenever’: here with the present indicative denoting repeated action.

stēkete proseuchomenoi ‘you stand up praying,’ ‘you stand in prayer’: this was the normal mode of prayer, among the Jews, with face lifted up to heaven.

stēkō (cf. 3.31) ‘stand.’

aphiete (cf. 2.5) ‘forgive’: if in a given language the verb requires an object, the Greek may be translated ‘forgive him against whom you have something.’

paraptōmata (only here in Mark) ‘transgressions,’ ‘trespasses’ (from parapiptō ‘fall alongside,’ ‘fall on the way’).

Translation:

Stand praying may require a translation involving a subordinate or coordinate relationship, e.g. ‘stand up to pray,’ ‘stand up and speak to God.’

For forgive see 1.4.

If you have anything against any one is translatable from two points of view: (1) what the offending person may have done, e.g. ‘if anyone has sinned against you’ (Kekchi), or (2) the attitude of the offended person as the result of the wrong committed, e.g. ‘if you are angry at anyone’ (Guerrero Amuzgo).

So that must be directly related to the verb ‘forgive,’ which, however, may be so far separated from the purpose clause that the meaning is lost, in which case one may use a transitional verb expression, e.g. ‘do this so that…’ or ‘forgive him so that….’

Also must be related to the ‘father’ or to the process of ‘forgiving’; it should not imply ‘also your father,’ meaning that God is also the father of you as well as the other person. To avoid this meaning also may be related to the verb ‘may also forgive you,’ even as you have forgiven the person in question. It is most important that also not be connected with ‘in heaven,’ as is done in some translations.

In this type of context it is often difficult to distinguish between ‘trespasses’ and ‘sins.’ In fact, in many languages one must use one and the same type of expression in all passages such as this (see 1.4 for words designating sin). In some languages, however, there are ways of making this distinction, e.g. ‘missing the commandment’ (Kipsigis) and ‘to step beyond the law’ (Navajo).

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 .