Psalm 100:5

For the Lord is good
Both in a providential way, and in a way of grace, and does good; he is the good Shepherd, that has laid down his life for the sheep; and the good Samaritan, that pours in the wine and oil of his love and grace, and his precious blood, to the healing of the wounds made by sin: while he was on earth, he went about doing good to the bodies and souls of men; and he continues to do good unto them, and therefore should be praised, served, and worshipped:

his mercy is everlasting;
or "his grace" ^F5; there is always a sufficiency of it for his people; and his lovingkindness, which may be also here meant, is always the same; having loved his own which were in the world, he loves them to the end, ( John 13:1 )

and his truth endureth to all generations;
or his faithfulness in fulfilling his promises, and performing his engagements; he was faithful to his Father that appointed him, and to the covenant he made with him; and he is faithful to his people, to keep what they commit to his care and charge now, and to give them the crown of righteousness at the last day, which is laid up for them; and upon all these considerations, and for these reasons, ought to be praised and adored.