This ad leaves out context. The 1st part, from 2016, deletes a line where Obama said he doesn't know Sanders as well as Clinton. The 2nd part is from 2006, not 2016, as the closing "Feel the Bern" snippet that is indeed from 2016 may suggest.
Here's the Sanders ad's version of the Obama quote, which is from a Politico interview in 2016, and the full Obama comment to Politico. 
Here's where Obama said the lines about Sanders being an honest leader and being somebody who will fight for the people. It's a 2006 speech in Vermont, when Obama was an Illinois senator supporting Sanders' Senate campaign.
Obama said "Feel the Bern" *as he was trying to persuade Sanders supporters to vote for Clinton.* He complimented their passion, then said, "We all need to get out and vote for Democrats up and down the ticket." There was a "Bern-ie" chant. He said, "That's right, feel the Bern."
