It was narrated from Busrah bin Safwan that the Prophet (May Allah bless him and grant him peace) said:
"Whoever touches his penis, he should not perform Salah until he performs Wudu'."
Narrated by the owners of the Sunan.
Commentary: The outward meaning of this hadith is that the one who touches his penis has no his wudu anymore. Many scholars understand this hadith as above.
But the Hanafi scholars understood it differently. They said, "The wudu in this hadith means washing the hands." This is because the word "wudu" means not only in the meaning of Shariah wudu, but also in the washing of hands. In the other hadith, the views of the Hanafi scholars are supported by the idea that zakar is also a member of a human being and wudu does not go away by detaining zakar.