In that April 2015 speech, Arnold reflected on what some consider the strangeness of a day of deep sadness being bracketed closely with national jubilation.
His speech, under the title Remembrance and Redemption, is the subject of the video embedded below.
He also shared aspects of a not-so-pleasant experience - as Israel's representative - addressing an international conference on terror and its victims, convened in New York City by the Secretary General of the United Nations in 2008. (A Haaretz report of that conference and of Arnold's speech is here.) That speech is the source of the audio track accompanying a short introductory film clip that was shown to the audience in Toronto and which takes up the first 4m 20s of the YouTube video clip.
[Sincere thanks to Mizrachi Canada for their permission to show this selection from their longer video recording (online here) of a memorable night of communal introspection and celebration.]