All of these narrations are to be understood as referring to someone who forgets the bowing (ruku’) in the first two rak’ahs, then in that case, it is obligatory for him to begin the prayer anew in all situations if he remembers. However, if the forgetfulness occurs in the last two rak’ahs and he remembers while still in the prayer, then he should disregard the two prostrations of the rak’ah in which he forgot the bowing and complete the prayer. What indicates this is what was narrated:
