At-Tawbah: 16
{ أَمْ } (Am) is munqati‘ah (disjunctive). The meaning of the hamzah within it is a rebuke for having entertained such a thought.
The meaning is: You will not be left as you are until those who are sincere among you are made manifest. They are those who have struggled in the way of Allah, for the sake of Allah, and have not taken a walijah—that is, an inner circle—from among those who oppose the Messenger of Allah (may Allah bless him and grant him peace) and the believers (may Allah be pleased with them).
{ وَلَمَّا } (Wa-lamma) signifies expectation. It indicates that the manifestation and clarification of this is expected and inevitable, and that those who have not purified their religion for Allah will be distinguished from the sincere ones.
His saying: { وَلَمْ يَتَّخِذُوا } (And have not taken) is conjoined to { جَاهَدُوا } (struggled), falling within the scope of the relative clause (silah). It is as if it were said: "And Allah has not yet known the strivers among you who are sincere, who have not taken an inner circle besides Allah."
{ الْوَلِيجَةُ } (Al-walijah) is in the form of fa‘ilah derived from walaja (to enter), just as dakhilah is derived from dakhala.
The intent behind the negation of "knowledge" is the negation of the "known object," similar to the saying of one who says: "Allah has not known from me what has been said about me," meaning: "He has not found that to be from me."
{ مَا كَانَ لِلْمُشْرِكِينَ أَنْ يَعْمُرُوا مَسَاجِدَ اللَّهِ شَاهِدِينَ عَلَىٰ أَنفُسِهِم بِالْكُفْرِ ۚ أُولَٰئِكَ حَبِطَتْ أَعْمَالُهُمْ وَفِي النَّارِ هُمْ خَالِدُونَ }