For whatsoever things were written aforetime were written for our learning (in the old sense of teaching, or instruction), that we through patience and comfort of the Scriptures (or, as the form of the Greek rather suggests, and as is confirmed by the repetition of the words conjoined in Romans 15:5, through the patience and the comfort of the Scriptures) might have hope.
This verse, introduced by γὰρ, gives the reason why the words of the ancient psalmist are adduced for the instruction of Christians. Christ, it is said, exemplified the principle of it, and it is for us to do so too.
By bearing the infirmities of the weak, and submitting, if need be, to reproach, we exhibit Christ-like endurance ( ὑπομονὴ), such as Scripture inculcates; and therewith will come comfort, such as Scripture contains and gives, and so a strengthening of our hope beyond these present troubles.
The psalm quoted was peculiarly one of endurance and comfort under vexations and reproaches, and of hope beyond them. It was written afore-time for our instruction, that so it may be with us, as it was with Christ.
In the next verse the apostle returns definitely to the subject in hand.