Exegesis:

kai parekalei auton polla ‘and he entreated him strongly’: the subject could be ‘the unclean spirits’ (with which auta ‘them’ would be in agreement) as Moffatt, Taylor, Manson and Goodspeed interpret it (cf. the parallel Lk. 8.31 ‘and they begged him’); it is probable, however (with American Standard Version, Revised Standard Version, Translator’s New Testament, The Modern Speech New Testament, O Novo Testamento de Nosso Senhor Jesus Cristo. Revisdo Autorizada, Lagrange and others), that the subject is ‘he’ (the man himself), as it is in the identical form parekalei ‘he begged’ in v. 18 (and notice the plural of the verb parekalesan ‘they (the spirits) begged’ in v. 12).

polla (cf. 1.45; 3.12) is adverbial ‘insistently,’ ‘strongly,’ ‘urgently.’

hina mē auta aposteilē ‘that he did not send them off’: the clause begun with hina ‘that’ denotes the content of the request – it is not a purpose clause (cf. 3.9, 12).

apostellō (cf. 1.2) ‘send away,’ ‘send.’

exō tēs chōras ‘outside the region’ (i.e. of the Gerasenes, v. 1): for chōra ‘region’ see 1.5.

Translation:

Begged him eagerly indicates the heart-felt nature of the entreaty, expressed in Tzotzil as ‘he asked with his heart coming out.’

In many languages the object of the entreaty must be in the form of direct discourse, e.g. ‘the man asked Jesus strongly, Do not send the unclean spirits away from this place.’ This type of expression need not imply any fond attachment which the man had for the demons which possessed him, but he uttered this request as the spokesman of the demons.

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 .