No speech of President Rodrigo Duterte of the Philippines would be complete without a cuss word or two thrown in. But not anymore.

Arriving in Davao City, Philippines on Thursday following a three-day state visit to Japan, Duterte surprised a welcoming audience at the airport when he promised that he would no longer utter cuss words during speeches after allegedly experiencing a spiritual epiphany on board the plane that took him home.

Duterte told GMA News that God talked to him on the plane.

"I was looking at the skies as I was coming over here. And I... everybody was asleep snoring. A voice said that you know 'If you don't stop [expletive], I will bring this plane down now.' And I said, who is this? Of course, it's God. Oh, OK. So, I promised God not to express slang, cuss words," he said.

"You guys hear me right always because a promise to God is a promise to the Filipino people," he added.

His announcement drew a huge round of applause from the crowd, Duterte jokingly told the crowd not to clap so hard, otherwise his plan to stop cursing would be nixed.

Curious reporters even asked Duterte if he would no longer cuss at his usual targets, namely the United States, the European Union, and Philippine Senator Leila de Lima, who is being accused of facilitating the illegal drug trade in the country's prison system and using drug money to finance her senatorial campaign.

The president simply replied, "There is always a time. A time to be foul-mouthed. I don't like anybody reading my mind. It's all calibrated, it's always timing. Watch out for one thing, that's what I've learned, miscalculation."

True to his word, Duterte did not curse once during his arrival speech.

Duterte's decision to remove cusswords from his speeches was swiftly welcomed by political analysts such as Teddy Locsin Jr., according to ABS-CBN News. "I don't think there is a problem in his manner of communicating because he's very clear," Locsin said. But he should "try to be little more politic in order to be less vulnerable to attack," said Locsin, who Duterte has named as Philippine ambassador to the United Nations.