Is a person rewarded for a deed if he performs it with an intention other than the intention upon which the reward is based, as in reciting Surat Al-Ikhlas ten times and its reward being the building of a house in Paradise? So, is someone who recites it in his prayers for several years, without knowing of this reward, rewarded for it?

The aforementioned Hadith indicates that reciting Surat Al-Ikhlas ten times outside of prayer builds a palace in Paradise for its reciter. As for reciting it within prayer, it has its own specific reward, and its reward varies according to the reader's intention. Thus, whoever recites it because it is equivalent to one-third of the Quran or because it contains a description of Allah, their reward is greater than someone who recites it for its speed. A servant is only rewarded the specific recompense for an action if they intended that upon which the reward is based. However, if a servant performs an action for the sake of Allah without knowing its specific reward, then the recompense is still recorded for them.