Offer the sacrifices of righteousness. Sacrifices of victims are scarcely meant; certainly not, if the time of the composition is that of David's exile, since victims could be offered nowhere but at Jerusalem.
We may suppose a reference to those sacrifices which are most truly "sacrifices of righteousness," vie. "a broken spirit, a broken and a contrite heart," which God "will not despise" (Psalms 51:17). And put your trust in the Lord.
Sacrifice without faith is vain. Even "sacrifices of righteousness," to be of any service, must be accompanied by trust in the Lord.