Complex sentence: The origin of this ceremony lies in the arranged marriage norm, where the parents would announce that they are looking for a suitable match for their son or daughter, and once they had found that match, their search had come to an end.
Split into simpler sentences: The origin of this ceremony lies in the arranged marriage norm where the parents would let out the word that they are looking for a suitable match for their son or daughter. And once they had found that match, their search had come to an end.