These three phrases are used together to mean "completely" or "earnestly." Here "heart" and "soul" are metonyms for a person's inner being. (See: [[rc://en/ta/man/translate/figs-metonymy]] and [[rc://en/ta/man/translate/figs-doublet]])
Here "great" and "first" mean the same thing. They emphasize that this is the most important commandment. (See: [[rc://en/ta/man/translate/figs-doublet]])