Does the ma'mum receive his full reward if he prays behind an imam who is praying while sitting?

The questioner : I ask our Shaykh regarding the hadith of Jabir, which our brother Wail mentioned. The hadith of Jabir indicates that whoever prays while sitting gets half the reward of the one who stands. Is this answer related to that, Shaykh? Is it in the voluntary prayer or the obligatory prayer?

The Shaykh : The hadith of Jabir does not indicate this. Where did you get that from?

The questioner : This is a benefit we derive from it.

The Shaykh : No, but you linked the issue to the hadith of Jabir. The hadith of Jabir contains nothing except that the Messenger (peace and blessings be upon him) was compelled to pray while sitting. But you are asking about the one who prays while sitting getting half the reward of the one who stands. You are asking about this hadith.

The questioner : Yes, in the case where the imam prayed while sitting and these people are compelled, it is obligatory for them to sit.

The Shaykh : Yes.

The questioner : So does the hadith include them regarding half the reward? Do they receive it or do they receive the full amount?

The Shaykh : The full amount.

The questioner : The full amount, because they followed the imam.