{Before his face} (en(9370)ion autou). Not in the ancient
Greek, but common in the papyri as in LXX and N.T. It is a
vernacular _Koin(825f) word, adverb used as preposition from
adjective en(9370)ios, and that from ho en (9370)i (936e) (the one who is
in sight). {Autou} here seems to be "the Lord their God" in verse
 16  since the Messiah has not yet been mentioned, though he was
to be actually the Forerunner of the Messiah. {In the spirit and
power of Elijah} (en pneumati kai dunamei Elei(835c)). See  Isa
40:1-11  Mal 3:1-5 . John will deny that he is actually Elijah in
person, as they expected ( Joh 1:21 ), but Jesus will call him
Elijah in spirit ( Mr 9:12  Mt 17:12 ). {Hearts of fathers}
(kardias pater(936e)). Paternal love had died out. This is one of
the first results of conversion, the revival of love in the home.
{Wisdom} (phron(8873)ei). Not sophia, but a word for practical
intelligence. {Prepared} (kateskeuasmenon). Perfect passive
participle, state of readiness for Christ. This John did. This is
a marvellous forecast of the character and career of John the
Baptist, one that should have caught the faith of Zacharias.