Complex sentence: A valid witness to an event in "halakhah" must have personally seen or heard the event; hearsay from another person is inadmissible, except in rare cases such as confirming that a missing husband has died (see Agunah).
Split into simpler sentences: A valid witness to an event in "halakhah" must have seen the event with his eyes or heard it with his ears. Generally hearsay from another person is inadmissible, except in rare cases such as confirming that a missing husband has died (see Agunah).