Sheikh Salman al-Oadah
Scholars have differed regarding the question of whether touching one’s penis nullifies one’s wudû’.
Some have said that touching one’s penis nullifies one’s wudû’ under all circumstances. They cite the hadîth related by Busrah bint Safwân: “Whoever touches his penis should perform wudû’.” [Sunan Abî Dâwûd (181), Sunan al-Tirmidhî (82), Sunan al-Nasâ’î (447) and Musnad Ahmad. (7076)]
Another opinion is that under no circumstances does touching one’s penis break wudû’. The text cited as evidence that touching the private parts does not nullify wudû’ is the hadîth where a man came to the Prophet (peace be upon him) and asked: “What do you think a man (should do) who touches his private part during prayer?”
The Prophet (peace be upon him) replied: “Is it not just a part of your body?” [Sunan al-Nasâ’î (165), Sunan al-Tirmidhî (82), Sunan Abî Dâwûd (182), Sunan Ibn Mâjah (483) and Musnad Ahmad (16286)]
Another opinion is that it is preferable to perform wudû’ after touching one’s private part but not obligatory.
A fourth opinion is that it touching one’s penis breaks wudû’ if sexual desire is involved. Otherwise it does not. These last two opinions take both hadîth into consideration.
In conclusion, I would say that it is safer to perform wudû’ after touching one’s penis, but it is not obligatory to do so.
And Allah knows best.
Source: Islam Today