balaṁ bhīmābhirakṣitam

aparyaptam-immeasurable; tat-that; asmakam-of ours; balam-strength; bhisma-by Grandfather Bhisma; abhiraksitam-perfectly protected; paryaptam-limited; tu-but; idam-all these; etesam-of the Pandavas; balam-strength; bhima-by Bhima; abhiraksitam-carefully protected.