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