We used not to call Zaid bin Haritha the freed slave of Messenger of Allah ﷺ except Zaid bin Muhammad till the Qu'anic Verse was revealed: "Call them (adopted sons) by (the names of) their fathers. That is more than just in the Sight of Allah." (33.5)
أَنَّ زَيْدَ بْنَ حَارِثَةَ مَوْلَى رَسُولِ اللَّهِ ﷺ مَا كُنَّا نَدْعُوهُ إِلاَّ زَيْدَ ابْنَ مُحَمَّدٍ حَتَّى نَزَلَ الْقُرْآنُ {ادْعُوهُمْ لآبَائِهِمْ هُوَ أَقْسَطُ عِنْدَ اللَّهِ}