The gaffe didn't go past director general of health Ashley Bloomfield was seen smirking just seconds later and raising his eye brows following Hipkins' humorous phrasing.
The moment caught the attention of many Kiwis across the country who took to Twitter to poke fun at the advice.
"Keep socially distanced when out spreading your legs," one wrote.
Another added a photoshoped Covid-19 advert telling people to "spread your legs", accompanied with the caption: "Latest official government advice, please retweet to get the message out."
A third said: "Chris Hipkins, saucy flirt."
A fourth said "Chris Hipkins accidentally saying spread their legs instead of stretch is exactly what we needed today."
SUNDAY COVID-19 UPDATE:
There are 21 new cases of Covid-19 in the community today, bringing the total number of people infected in the outbreak to 72.
Hipkins wouldn't reveal when Kiwis could expect to come out of alert level 4, though suggested different restrictions could be applied to different regions. Cabinet is due to meet tomorrow to decide on alert levels.
"We will give people plenty of notice," Hipkins said at today's 1pm press conference.
"There's still more information to gather."
The Government has also decided to make Covid QR code scanning or record keeping at businesses mandatory.
One new case is in Wellington, the other cases are all in Auckland, Bloomfield said.
Five people are in hospital due to Covid-19, but none are in ICU.
Sixty-one of the cases in the outbreak are confirmed as part of the same cluster, with the other 11 under investigation but with likely links.
Bloomfield said some of the 11 cases not formally linked to the cluster were University of Auckland students.
ESR is running whole-genome sequencing, and those matched to the cluster are all "largely identical", he said.
Bloomfield said "just a few, less than 10" people with Covid had opted to go into MIQ instead of self-isolating at home.
The Holiday Inn near the Auckland Airport was the facility repurposed for people needing to isolate who couldn't do so at home.
Bloomfield said anyone self-isolating should do so within their bubble.
Bloomfield said several of the new cases are linked to a service at the Samoan Assembly of God church in Māngere last Sunday. This was emerging as a cluster within the outbreak, he said.
People who attended are being asked to call Healthline for advice on testing.
The Samoan Assembly of God Church in Māngere is now a location of interest.
Anyone there between 9am and 3pm on Sunday August 15 is asked to isolate at home for 14 days and seek Covid tests on day 5 and day 12.
Both Wellington and Auckland airport domestic terminals are now locations of interest.
University of Auckland's Engineering Building City Campus is also a location of interest.
From today, locations of interest will be updated automatically on a two-hourly basis. Any significant or urgent locations of interest will be published as required.
As of 9am, 8667 individual contacts have been identified - the majority being close contacts, the ministry said. The number will increase throughout the day, as records are fully processed.
"Of these contacts, 4124 have been contacted and are self-isolating, and a third have had a test.
"Work is under way to contact the remaining 4500 contacts. Most of these contacts were identified yesterday as a result of case investigations into settings with high numbers of people involved (eg, schools)," health officials say.
