"Indeed, those who have believed and those who were Jews and the Sabi'un (Sabians) and the Christians - those who believed in Allah and the Last Day" - meaning: those of them who believed in Muhammad and entered into his religion and his law.
Muhammad said: There is a difference of opinion regarding the nominative case (raf') of the word "al-Sabi'un". The best view is that it is understood as being postponed and is in the nominative case by virtue of being an initial subject (ibtida'). The meaning is: "Indeed, those who have believed and those who were Jews - whoever believed in Allah and the Last Day and did righteousness - then no fear will be upon them (fol. 86), and [likewise] the Sabi'un and the Christians."
﴿إِنَّ الَّذِينَ آمَنُوا وَالَّذِينَ هَادُوا والصابئون وَالنَّصَارَى مَنْ آمَنَ مِنْهُمْ بِاللَّهِ وَالْيَوْمِ الآخر﴾ يَعْنِي: مَنْ آمَنَ مِنْهُمْ بمحمدٍ، وَدَخَلَ فِي دِينِهِ وَشَرِيعَتِهِ.
قَالَ مُحَمَّدٌ: اخْتَلَفَ الْقَوْلُ فِي رَفْعِ ﴿الصابئون﴾ وَالْأَجْوَدُ أَنَّهُ مَحْمُولٌ عَلَى التَّأْخِيرِ، وَمَرْفُوعٌ بِالِابْتِدَاءِ، الْمَعْنَى: إِنَّ الَّذِينَ آمَنُوا وَالَّذِينَ هَادُوا مَنْ آمَنَ بِاللَّهِ وَالْيَوْمِ الآخِرِ وَعَمِلَ صَالِحًا - فَلَا خوف عَلَيْهِم، (ل ٨٦) والصابئون وَالنَّصَارَى
