Pursue the performance of even a "minor" mitzvah (Ethics of the Fathers 4:2).
How does one pursue a mitzvah?
Rabbi Moshe Leib of Sassov used to occupy himself with redeeming Jews from debtors' prisons. Usually, these people had been thrown into dungeons because they could not pay the rent demanded by the poritz (feudal lord). On one visit to such a prison, Rabbi Moshe Leib was unable to gain the release of a debtor, and gave up trying. He then saw another prisoner being flogged mercilessly, and he was able to get him released. Subsequently, he discovered that this latter person was not a debtor but one who was imprisoned for stealing.
"Well," said the Rabbi, "now you have been taught your lesson. After that flogging you will certainly never steal again."
"Why not?" the thief responded. "Just because I was caught this time does not mean that I will not succeed next time."
Rabbi Moshe Leib felt that these words were directed at him. Just because he had failed once to ransom a debtor, he did not have the right to resign himself to failure. He retraced his steps and renewed his efforts to redeem the debtor. Next time he might succeed.
That is what is meant by pursuit of a mitzvah. If a specific mitzvah eludes you, do not resign yourself, but pursue it until you overtake and fulfill it.