And indeed, the tanween is a substitute for the added noun. It means: And indeed all of them, and indeed all those who differ in it will certainly be given their due as a response to an omitted oath. The 'lam' in 'lamma' serves as an introduction to the oath, and 'ma' is an addition. The meaning is: And indeed all of them, by Allah, your Lord will certainly give them their deeds, whether good or bad, faith or denial. It has been recited: And indeed all, with a lightening of the form, applying the lightened form as if it were heavy, considering its original form which is the heavy one. And Ubayy read: And indeed all, when it is said that 'in' is negating. And 'lamma' means except. The reading of Abdullah clarifies this. And indeed all except will certainly be given their due. And Al-Zuhri and Sulayman ibn Arqam read: And indeed all, when it is said that 'lamma' is with tanween, like his saying 'aklan lamma'. The meaning is: And indeed all are gathered, as if it were said: And indeed all together, like his saying: So the angels prostrated, all of them together.