While the Prophet ﷺ was in the market, a man called (somebody), "O Abu-l-Qasim!' The Prophet ﷺ turned to him and said "Name yourselves after me but do not call yourselves by my Kuniya."

كَانَ النَّبِيُّ ﷺ فِي السُّوقِ فَقَالَ رَجُلٌ يَا أَبَا الْقَاسِمِ فَالْتَفَتَ النَّبِيُّ ﷺ فَقَالَ سَمُّوا بِاسْمِي وَلاَ تَكْتَنُوا بِكُنْيَتِي

While the Prophet ﷺ was in the market, somebody, called, "O Abul-Qasim." The Prophet ﷺ turned to him. The man said, "I have called to this (i.e. another man)." The Prophet ﷺ said, "Name yourselves by my name but not by my Kunya (name)." (In Arabic world it is the custom to call the man as the father of his eldest son, e.g. Abul-Qasim.) (See Hadith No. 737, Vol. 4)

كَانَ النَّبِيُّ ﷺ فِي السُّوقِ فَقَالَ رَجُلٌ يَا أَبَا الْقَاسِمِ فَالْتَفَتَ إِلَيْهِ النَّبِيُّ ﷺ فَقَالَ إِنَّمَا دَعَوْتُ هَذَا فَقَالَ النَّبِيُّ ﷺ سَمُّوا بِاسْمِي وَلاَ تَكَنَّوْا بِكُنْيَتِي

A man at Al-Baqi' called, "O Abul-Qasim!" The Prophet ﷺ turned to him and the man said (to the Prophet ), "I did not intend to call you." The prophet said, "Name yourselves by my name but not by my Kunya (name).

عَنْ أَنَسٍ ؓ دَعَا رَجُلٌ بِالْبَقِيعِ يَا أَبَا الْقَاسِمِ فَالْتَفَتَ إِلَيْهِ النَّبِيُّ ﷺ فَقَالَ لَمْ أَعْنِكَ قَالَ سَمُّوا بِاسْمِي وَلاَ تَكْتَنُوا بِكُنْيَتِي