His statement, "he pours water over himself," indicates that the amount of water used is greater than the residual amount of urine, as it would only be poured in an amount that exceeds the remaining impurity.
Then he (Shaykh Al-Mufid) said: "If someone becomes junub (ritually impure due to sexual activity) and wishes to perform ghusl (ritual bathing), they should not place their hand in the water vessel until they wash it three times. If performing wudu (ablution) after relieving oneself, they should wash their hands twice before placing them in the water, as we have mentioned. For impurity caused by urination, they should wash their hands once before placing them in the vessel, and the same applies to impurity caused by sleep." What indicates this is (following hadith):
Commentary #23