This is the 165th most frequent Slovenian word.
svoj
"Own" or "one's own."
Here, 'svoje' is a form of 'svoj' used to express possession of hands, referring back to the subject 'I'.
Vsako jutro si umijem svoje roke.
Every morning, I wash my own hands.
In this sentence, 'svojega' refers to relation or ownership between the 'teacher' and his 'student'.
Učitelj je pohvalil svojega učenca za dobro opravljeno nalogo.
The teacher praised his student for a task well done.
'Svojih' in this sentence is tied to 'močných', expressing one's maximum abilities, referring to Maria.