John Calvin Commentary Psalms 119:125

"I am thy servant; give me understanding, That I may know thy testimonies." — Psalms 119:125 (ASV)

I am your servant, give me understanding. Here the prayer of the preceding verse is repeated. The repetition shows how ardently he desired the blessing prayed for, and how earnest and persistent he was in pleading with God for it. With these words, he expresses even more plainly how God teaches His own people: He does so by illuminating their understandings with sound knowledge, which would otherwise be blind.

It would profit us little to have the divine law sounding in our ears, or to have it displayed in writing before our eyes, and to have it expounded by human voices, if God did not correct our slowness of apprehension and make us teachable by the secret influence of His Spirit.

We should not suppose that David makes any meritorious claims before God when he boasts of being His servant. Indeed, people commonly imagine that when we are previously well prepared, God then adds new grace, which they term subsequent grace.

But the Prophet, so far from boasting of his own worth, instead declares how deep his obligations to God were. It is not in anyone's power to make himself a servant of the Most High, nor can anyone bring anything of his own as a price to purchase so great an honor.

The Prophet was well aware of this. He knew that not one in the entire human family is worthy of being counted in that order; therefore, he does nothing more than present the grace he had received as an argument that God, according to His usual way, would complete what He had begun. In a similar manner, he speaks in Psalm 116:16,

I am your servant and the son of your handmaid:

In this passage, it is abundantly clear that he does not boast of his services, but only declares that he is one of the members of the Church.