1 Samuel 30:6
And David was greatly distressed; for the people spake of stoning him, because the soul of all the people was grieved, every man for his sons and for his daughters: but David encouraged himself in the LORD his God. And David was greatly distressed; for the people spake of stoning him, because the soul of all the people was grieved, every man for his sons and for his daughters: but David encouraged himself in the LORD his God.
David was greatly distressed when human support had failed him and he was left surrounded by grief and danger. His own grieving people turned against him in rejection, every man grieved for his sons and for his daughters, and they spoke of stoning him. In that abandonment he turned to God for help and encouraged and strengthened himself in the Lord his God.
He found that strength by recalling the Lord's past care for him. Though afraid, he trusted God, confident that God could see a way forward and would guide him in what to do. The Lord stands in the verse as the source of strength in hardship, and those under heavy burdens are to let the heart find strength in God.