Was Islam spread by the sword? 2

The period when Islam flourished, during the lifetime of the Prophet (peace and blessings of Allah be upon him) was after the truce of huddayybiah. Over a period of one and a half years more people became Muslims in this period than ever before. This is written by Ibn Kathir and many others. Which sword made them do this? It wasn't a sword it was seeing changed human beings who were amazing thats what converted them and thats what people don't understand.