It is narrated from Sayyida Busrah bint Safwan (may Allah be pleased with her) that she heard the Prophet (peace and blessings be upon him) say: "When any one of you touches his private part, he should perform ablution." Imam Malik (may Allah have mercy on him) says that in his view, performing ablution after touching the private part is recommended (mustahabb); he does not consider it obligatory. Janab Ali bin Saeed Naswi says that he asked Imam Ahmad bin Hanbal (may Allah have mercy on him) about performing ablution after touching the private part, and he replied that he considers it recommended (mustahabb), not obligatory.