τη definite article - dative singular feminine
ho  ho: the definite article; the (sometimes to be supplied, at others omitted, in English idiom) -- the, this, that, one, he, she, it, etc.
προσευχη noun - dative singular feminine
proseuche  pros-yoo-khay': prayer (worship); by implication, an oratory (chapel) -- pray earnestly, prayer.
προσκαρτερειτε verb - present active middle - second person
proskartereo  pros-kar-ter-eh'-o: to be earnest towards, i.e. (to a thing) to persevere, be constantly diligent, or (in a place) to attend assiduously all the exercises, or (to a person) to adhere closely to (as a servitor)
γρηγορουντες verb - present active passive - nominative plural masculine
gregoreuo  gray-gor-yoo'-o: to keep awake, i.e. watch -- be vigilant, wake, (be) watch(-ful).
εν preposition
en  en: in, at, (up-)on, by, etc.
αυτη personal pronoun - dative singular feminine
autos  ow-tos': the reflexive pronoun self, used of the third person , and (with the proper personal pronoun) of the other persons
εν preposition
en  en: in, at, (up-)on, by, etc.
ευχαριστια noun - dative singular feminine
eucharistia  yoo-khar-is-tee'-ah: gratitude; actively, grateful language (to God, as an act of worship) -- thankfulness, (giving of) thanks(-giving).