Hadith: Is it not but a piece of him

عن طلق بن علي رضي الله عنه قال: قَدِمْنَا على نَبِيِّ الله صلى الله عليه وسلم فجاء رَجُل كأنه بَدَوي، فقال: يا نَبِيَّ الله، ما ترى في مَسِّ الرَّجل ذَكَره بعد ما يتوضأ؟ فقال: «هل هو إلا مُضْغَةٌ منه»، أو قال: « بَضْعَةٌ منه».
[صحيح] - [رواه أبو داود وأحمد والترمذي والنسائي]

Talq ibn ‘Ali (may Allah be pleased with him) reported: We went to the Prophet (may Allah's peace and blessings be upon him) and a man, who seemed to be a Bedouin, came forward and said: "O Prophet, what do you say regarding the man who touches his penis after making ablution?" The Prophet (may Allah's peace and blessings be upon him) said: "Is it not but a piece of him." Or he said: "a part of him."
Sahih/Authentic. - [At-Tirmidhi]

Explanation

The question: "What do you say regarding the man who touches his penis after making ablution?", i.e. what is the religious ruling regarding touching the penis after making ablution; is there anything that one has to do? In a narration from Ahmad: "A man touches his penis in the prayer, does he have to make ablution (again)?" He (the Prophet) said: "No, it is only a part of you." The statement: "Is it not but a piece of him," or "a part of him", i.e. the penis is like the rest of the body parts. If someone who is in the state of ablution touches his hand or leg or nose or head, this will not nullify his ablution. The same applies if he touches his penis. This Hadīth is either abrogated or it is understood to mean touching the penis with a barrier, such as touching it from over the clothes. As for touching it directly with the hand, this nullifies ablution as stated in other Hadīths.