Is it obligatory to repeat the Dhuhr prayer if the worshiper performed ablution a few minutes before its time, knowing that his ablution was not nullified until he performed the prayer?

One afflicted with incontinence performs ablution after the time for prayer begins if the discharge is continuous, such that they cannot find a time to perform prayer with valid purity. However, if the incontinent person performs ablution before the time for prayer begins, and no discharge occurs after the time for prayer begins, then their prayer and purity are valid.