I think I might have misunderstood a fatwa from Sayed Sistani. Here is the rulings im confused about below, hopefully you can clarify what they mean.

Ruling 1138. If during prayers one remains silent to the extent that it cannot be said he is performing prayers, his prayer becomes invalid.

Ruling 1139. If during prayers one does something or remains silent for a while and doubts whether or not his prayer has broken up, he must perform the prayer again. However, it is better that he first completes that prayer and then repeats it.

Does this mean reciting the prayer silently or doing nothing such as standing or sitting in silence for a while?

Silent means doing or saying nothing