When Al-Mundhir bin Abu Usaid was born, he was brought to the Prophet ﷺ who placed him on his thigh. While Abu Usaid was sitting there, the Prophet ﷺ was busy with something in his hands so Abu Usaid told someone to take his son from the thigh of the Prophet ﷺ . When the Prophet ﷺ finished his job (with which he was busy), he said, "Where is the boy?" Abu Usaid replied, "We have sent him home." The Prophet ﷺ said, "What is his name?" Abu Usaid said, "(His name is) so-and-so. " The Prophet ﷺ said, "No, his name is Al-Mundhir." So he called him Al-Mundhir from that day.  

أُتِيَ بِالْمُنْذِرِ بْنِ أَبِي أُسَيْدٍ إِلَى النَّبِيِّ ﷺ حِينَ وُلِدَ فَوَضَعَهُ عَلَى فَخِذِهِ وَأَبُو أُسَيْدٍ جَالِسٌ فَلَهَا النَّبِيُّ ﷺ بِشَىْءٍ بَيْنَ يَدَيْهِ فَأَمَرَ أَبُو أُسَيْدٍ بِابْنِهِ فَاحْتُمِلَ مِنْ فَخِذِ النَّبِيِّ ﷺ فَاسْتَفَاقَ النَّبِيُّ ﷺ فَقَالَ أَيْنَ الصَّبِيُّ فَقَالَ أَبُو أُسَيْدٍ قَلَبْنَاهُ يَا رَسُولَ اللَّهِ قَالَ مَا اسْمُهُ قَالَ فُلاَنٌ قَالَ وَلَكِنْ أَسْمِهِ الْمُنْذِرَ فَسَمَّاهُ يَوْمَئِذٍ الْمُنْذِرَ  

Where is the child? Abd Usaid said: Messenger of Allah, we took him away. He said: What is his name? He said; Messenger of Allah, it is so and so, whereupon he (the Holy Prophet) said: Nay, his name is Mundhir, and named him Mundhir on that day. (Using translation from Muslim 2149)   

أُتِيَ بِالْمُنْذِرِ بْنِ أَبِي أُسَيْدٍ إِلَى رَسُولِ اللهِ ﷺ حِينَ وُلِدَ فَوَضَعَهُ عَلَى فَخِذِهِ وَأَبُو أُسَيْدٍ جَالِسٌ قَالَ فَلَهَا النَّبِيُّ ﷺ بِشَيْءٍ بَيْنَ يَدَيْهِ فَأَمَرَ أَبُو أُسَيْدٍ بِابْنِهِ فَاحْتُمِلَ مِنْ عِنْدِ النَّبِيِّ ﷺ فَأَقْلَبُوهُ فَاشْتَاقَ النَّبِيُّ ﷺ فَقَالَ «أَيْنَ الصَّبِيُّ؟» قَالَ أَبُو أُسَيْدٍ أَقْلَبْنَاهُ يَا رَسُولَ اللهِ قَالَ «مَا اسْمُهُ؟» قَالَ فُلَانٌ قَالَ «لَا وَلَكِنِ اسْمُهُ الْمُنْذِرُ» فَسَمَّاهُ يَوْمَئِذٍ الْمُنْذِرَ  

When Al-Mundhir bin Abu Usaid was born, he was brought to the Prophet ﷺ who placed him on his thigh. While Abu Usaid was sitting there, the Prophet ﷺ was busy with something in his hands so Abu Usaid told someone to take his son from the thigh of the Prophet ﷺ . When the Prophet ﷺ finished his job (with which he was busy), he said, "Where is the boy?" Abu Usaid replied, "We have sent him home." The Prophet ﷺ said, "What is his name?" Abu Usaid said, "(His name is) so-and-so. " The Prophet ﷺ said, "No, his name is Al-Mundhir." So he called him Al-Mundhir from that day. (Using translation from Bukhārī 6191)   

أُتِيَ بِالْمُنْذِرِ بْنِ أَبِي أُسَيْدٍ إِلَى رَسُولِ اللهِ ﷺ حِينَ وُلِدَ فَوَضَعَهُ عَلَى فَخِذِهِ وَأَبُو أُسَيْدٍ جَالِسٌ فَلَهَى النَّبِيُّ ﷺ بِشَيْءٍ بَيْنَ يَدَيْهِ فَأَمَرَ أَبُو أُسَيْدٍ بِابْنِهِ فَاحْتُمِلَ مِنْ عَلَى فَخِذِ النَّبِيِّ ﷺ فَأَقْلَبُوهُ فَقَالَ رَسُولُ اللهِ ﷺ أَيْنَ الصَّبِيُّ؟ فَقَالَ أَبُو أُسَيْدٍ أَقْلَبْنَاهُ يَا رَسُولَ اللهِ قَالَ مَا اسْمُهُ؟ قَالَ فَلَانٌ قَالَ لَا وَلَكِنِ اسْمُهُ الْمُنْذِرُ فَسَمَّاهُ يَوْمَئِذٍ الْمُنْذِرَ  

Sahl said, "Al-Mundhir ibn Abi Usayd was brought to the Prophet, may Allah bless him and grant him peace, when he was born and the Prophet placed him on his thigh while Abu Usayd was seated near him. The Prophet, may Allah bless him and grant him peace, was busy with something in front of him, so Abu Usayd told someone to take his son from the Prophet's leg. When the Prophet, may Allah bless him and grant him peace, became aware of it, he asked, 'Where is the child?' Abu Usayd replied, 'We sent him home.' The Prophet asked, 'What is his name?' He replied, 'Such-and-such.' The Prophet said, 'No, rather his name is al-Mundhir.' So we called him al-Mundhir from that day."  

عَنْ سَهْلٍ قَالَ أُتِيَ بِالْمُنْذِرِ بْنِ أَبِي أُسَيْدٍ إِلَى النَّبِيِّ ﷺ حِينَ وُلِدَ فَوَضَعَهُ عَلَى فَخِذِهِ وَأَبُو أُسَيْدٍ جَالِسٌ فَلَهَى النَّبِيُّ ﷺ بِشَيْءٍ بَيْنَ يَدَيْهِ وَأَمَرَ أَبُو أُسَيْدٍ بِابْنِهِ فَاحْتُمِلَ مِنْ فَخِذِ النَّبِيِّ ﷺ فَاسْتَفَاقَ النَّبِيُّ ﷺ فَقَالَ أَيْنَ الصَّبِيُّ؟ فَقَالَ أَبُو أُسَيْدٍ قَلَبْنَاهُ يَا رَسُولَ اللهِ قَالَ مَا اسْمُهُ؟ قَالَ فُلاَنٌ قَالَ لاَ لَكِنِ اسْمُهُ الْمُنْذِرُ فَسَمَّاهُ يَوْمَئِذٍ الْمُنْذِرَ