Exegesis:

dia pantos nuktos kai hēmeras ‘continually, night and day.’

ēn krazōn kai katakoptōn ‘he was shrieking and cutting.’

krazō (cf. 3.11) ‘shriek,’ ‘cry out,’ ‘shout.’

katakoptō (only here in N.T.) ‘cut,’ ‘gash’: Field contends for the meaning ‘beating himself,’ which the verb sometimes has. The great majority of commentators and translations, however, prefer the usual meaning.

lithois (12.10; 13.1, 2; 15.46; 16.3, 4) ‘with stones,’ ‘with rocks.’

Translation:

Night and day, as an expression of ‘all the time’ or ‘continually,’ may in some instances need to be altered in order, e.g. ‘day and night,’ depending on the more usual order of speaking. On the other hand, it may be necessary to expand the phrase somewhat, e.g. ‘all the time, both night and day,’ in order that the reader may understand this action as continuous.

Crying out is here ‘shrieking,’ ‘howling,’ and ‘screaming.’

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 .