The moment was in full view of cameras and those standing on the tarmac, but that didn't prevent her from doing it - although that may be because she didn't think there was anything in it.
According to the below popular Twitter account named "Rogue White House Senior Advisor", a Twitter account with a location that claims its from the West Wing - one that enjoys more than 90,000 Twitter followers, there was a heated response to Melania's hand slap video.
A CNN digital editor tweeted a GIF of the Rome hand "swat" captioned, "When in Rome", shortly after 12:30 p.m.
Looking towards his wife, Mr Trump reached out his hand, seemingly for Melania to hold. They briefly held hands in Saudi Arabia as they entered the Global Center for Combating Extremist Ideology. The two were first seen not holding hands while touring the Church of the Holy Sepulchre before walking the streets of the Old City, where again their hands did not meet. Trump became the first sitting president to visit the holy site, where he was accompanied by the Western Wall's rabbi, Shmuel Rabinovitz. Or maybe there was a bug.
If it was indeed intentional, it's not the first time the first lady has used body language publicly to steer her husband.
At the annual Easter Egg hunt she had to remind her husband to raise his hand to his heart while the national anthem was being sung.
"We have all this protocol, but we never know what to do", the prime minister said to Mr Trump.