Is it obligatory or recommended for the judge to question witnesses about their state frequently?

Primary text

Ahmad holds that the judge should inquire about the state of his witnesses frequently because a person's condition changes over time. There are two views on whether this inquiry is recommended or obligatory. The first view states it is recommended (*mustahabb*) because the default is the continuation of the previous state, which does not cease unless the invalidation (*jarh*) is established. The second view states it is obligatory (*wajib*) to investigate whenever a period passes in which conditions might change, due to the possibility of defects emerging, and this obligation rests upon the judge's discretion.