Patrick A. Tiller, «Reflexive Pronouns in the New Testament», Vol. 14 (2001) 43-63
The purpose of this study is to answer two basic 
      questions concerning reflexive and reciprocal pronouns in the New 
      Testament: (1) What are the syntactic constraints on reflexives, that 
      determine when they may be used? (2) What are the semantic constraints 
      that determine when in fact they are used? In answering the first question 
      the author considers both reflexives and reciprocals and discuss the whole 
      NT; for the second, the author attempts to suggest answers for third 
      person reflexives and based only on the Pauline Epistles commonly 
      recognized as authentic.
Reflexive Pronouns in New Testament                                                  61
   1 Thess 2:7 w~ eja;n trofo;~ qavlph/ ta; eJauth`~ tevkna, ...
                 J
               as when a-nurse cherishes the of-herself children, ...
   Rom 16:4 oitine~ uJpe;r th`~ yuch`~ mou to;n eJautw'n travchlon uJpevqhkan...
                   {
               who for the life of-me the of-themselves neck risked ...
               ... who risked their own necks for my life ...
   Rule 8         When a pronoun is optionally reflexive according to Rule
                  7, then it will be reflexive if and only if one of the follow-
                  ing conditions is true:
                  1. the referent of the pronoun is contrasted with some-
                  thing else;
                  2. the trigger is the agent of the action that is received by
                  the pronoun, and the NP that governs the pronoun is
                  either part of the body or of the family of the referent of
                  the trigger.
    The next examples show that both parts of condition (2) must equal-
ly apply in order to cause the pronoun to be reflexive. In the first extend-
ed passage, the words parqevnon (‘virgin’)21 and kardiva (‘heart’) are body
parts or (extended) family members of the referent of the trigger.
   1 Cor 7:36-37 36Eij dev ti~ ajschmonei`n ejpi; th;n parqevnon aujtou` nomivzei,
                 If but someone to-be-indecent toward the virgin of-him thinks,
                 ean h\/ uJpevrakmo~
                    j;                               kai; ou{tw~ ojfeivlei givnesqai,
                 if she-is past-marriageable-age and thus it-ought to-be,
                 o;J qevlei         poieivtw, oujc aJmartavnei, gameivtwsan.
                 what he-wishes let-him-do, not he-sins, let-them-marry.
                 37
                     o~J     de; e[sthken ejn th'/ kardiva/ aujtou`
                 Whoever but stands in the heart of-him
                 eJdrai`o~ mh; e[cwn ajnavgkhn, ejxousivan de; e[cei peri;
                 steadfast not having necessity, authority but he-has concerning
                 tou` ijdivou qelhvmato~ kai; tou`to kevkriken           ejn th'/ ijdiva/
                 the his-own will          and this he-has-judged in the his-own
                 kardia, threi`n th;n eJautou` parqevnon, kalw'~ poihvsei.
                          v/
                 heart, to-keep the of-himself virgin,              well he-will-do.
                 But if someone thinks that he is acting indecently toward his
                 virgin, if she is past the age of marriage and it must be so, let
                 him do what he wishes – he does not sin; let them be married.
                 But whoever stands steadfast in his heart, without necessity,
                 and if he has control over his own will and has determined in
                 his own heart to keep his own virgin, he will do well.
   21
      What the word refers to in this passage is problematic. Probably, «The reference is
to women in the community who have agreed to set up house with a man in order that
they may achieve the ideal of Christian asceticism in economic independence.» Gerhard
Delling, «parqevno~,» TDNT 5 (1968) 836.