Is it necessary to focus and contemplate the meanings of the supplications mentioned in the noble prophetic traditions in order to obtain their reward, or is merely uttering them sufficient?

There is no requirement to ponder the meaning of the remembrances (dhikr) to obtain the reward associated with them, for the reward is established merely by uttering them with the tongue. The presence of the heart and contemplation are recommended and add extra reward, making the remembrance more complete and impactful on the heart. Remembrance with the tongue is better than silence and earns reward, even if it is incomplete compared to the action of the heart. The specific reward for remembrance does not require contemplation, but contemplation makes it more perfect and complete.