Psalm 40:10

I have not not hid thy righteousness within my heart
Meaning not the essential righteousness of God, though that was abundantly declared in the wounds, sufferings, and death of Christ; and which was the end indeed of his being a propitiation for sin, ( Romans 3:25 Romans 3:26 ) ; but his own righteousness, as before, which he wrought out, and brought in; and which is called the righteousness of God his Father, because it is approved of by him, and accepted with him, and which he imputes to all his people;

I have declared thy faithfulness and thy salvation:
trial is, the "faithfulness" of God in executing all his purposes, counsels, and decrees, which are said to be faithfulness and truth; and in fulfilling his covenant and promises, relating to the redemption and salvation of men by Christ; and in the mission of Christ into this world on that account; and in the accomplishment of all the prophecies of the Old Testament concerning him; and in making good all the particular promises of support, help, and strength, made to the Messiah himself: and by his "salvation" is meant, that which is of God the Father's appointing, continuing, and settling, in the council and covenant of grace; which he sent his Son to be the author of, and which he has obtained; and is the great doctrine of the Gospel preached by himself, and his faithful ministers, ( Luke 19:9 Luke 19:10 ) ( Mark 16:16 ) ;

I have not concealed thy lovingkindness and thy truth from the great
congregation;
or "in the great congregation", as the Targum. By the "lovingkindness" of God is designed both his love to Christ, which was before the foundation of the world, and continued in his lowest state of humiliation, and which our Lord was far from concealing, but gave openly instances of it, ( John 17:24 ) ( 10:17 ) ( 5:20-23 ) ; and this love to his people; and which he declared to be the same with that which he is loved with, and instances in the gift of himself to them by his Father, as the great evidence of it, ( John 17:23 ) ( 3:16 ) ; and by "truth" is intended the Gospel in general, which came by Christ, was preached by him, which he bore witness to, to do which was one end of his coming into the world; and this was not concealed by him, who is truth itself; but was fully and plainly declared by him, as it had not been before, ( John 1:17 ) ( 18:37 ) .