President Donald Trump lauded America’s ties to Ireland by quoting one of his favorite “Irish” proverbs ― except that it probably wasn’t Irish at all.

Standing alongside Irish Prime Minister Enda Kenny at the Friends of Ireland luncheon in Washington, D.C., on the eve of St. Patrick’s Day on Thursday, Trump said that “as we stand together with our Irish friends” he was “reminded of that proverb” he’d heard “for many, many years and I love it.”

“Always remember to forget the friends that proved untrue, but never forget to remember those that have stuck by you,” recited Trump. “We know that, politically speaking.”

But many Irish people questioned the authenticity of his saying.

As an Irish person I can safely say I have never, ever heard this proverb #trump #paddywhackery https://t.co/bvEzDjSNse — Andrew McDermott (@AndrewMcD999) March 16, 2017

Have literally never heard this in my entire life. https://t.co/3gSBhbvdl2 — Christine Bohan (@ChristineBohan) March 16, 2017

This is utter bollocks Trump



'Irish proverb' my arse https://t.co/kK4BEUbxHD — Planet Belfast (@Planet_Belfast) March 16, 2017

With all due respect to the president's reputation for scrupulously checking his sources, I don't think this is an Irish proverb. https://t.co/1EvGGMsE9r — The Irish For 🏌🐕 (@theirishfor) March 16, 2017

Some Twitter users suggested that a member of Trump’s team had simply plucked the saying from one of the multiple websites on which it’s dubiously listed as an old Irish proverb:

Trump's Irish Proverb may have been written by Albashir Adam Alhassan but to be fair it IS in the second Google hit for "Best Irish Proverb" pic.twitter.com/53sXOi1EHr — Cabel Sasser (@cabel) March 16, 2017

One of his staff is definitely trolling him now, and it's brilliant

Trump: 'quick, find me an Irish proverb!'

Staffer: 'Sure Mr President.. https://t.co/cCuOyh1afV — Vanessa Furey (@VanessaFurey) March 16, 2017

Others claimed the line actually emanated from the poem “Remember to forget,” by Nigerian poet Albashir Adam Alhassan, to whom The Huffington Post has reached out for comment.

This is not an Irish proverb. It's a poem by Albashir Adam Alhassan, who is Nigerian. https://t.co/5DYxflz9v5 — Scott Hanselman (@shanselman) March 16, 2017

Albashir Adam Alhassan wrote the poem Trump quoted as his favorite Irish Proverb! Fyahn Nigerian that he is!

Thanx @colz for finding poem! pic.twitter.com/S3uJ2xtF8D — Black Madonna (@AnasuyaIam) March 16, 2017

Mashable also notes how Joanne Tuttle claims the phrase in her online book of poems, Crystal Inspirations.

In fairness to Trump, he didn’t explicitly state that the saying was Irish ― but Twitter users were unwilling to let him off the hook, given that he said he was prompted to say it while standing “together with our Irish friends.”

While the origin of the phrase remains unclear, a White House spokeswoman explained its appearance in Trump’s speech to The Hill by saying it was “originally supplied in an email on March 8 by the State Department via [the National Security Council] as building blocks in advance of this event,”

“These building blocks were supplied in the context of the Shamrock Ceremony and were ultimately used in the prepared remarks for the luncheon,” she added.