'Strength' in the Bible

And Judah said, The strength of the bearers of burdens faileth, and there is much rubbish; so that we are not able to build at the wall.

And he said to them, Go your way, eat the fat, and drink the sweet, and send portions to them for whom nothing is prepared; for the day is holy to our Lord; and be not grieved, for the joy of Jehovah is your strength.