Manila: Loud-mouthed and firebrand President Rodrigo Duterte vowed to speak clean language from now on, adding that people will no longer hear him curse and use profanity-laced expressions.

Narrating his sudden change of heart and tongue Duterte said, “I was looking at the sky as I was coming over here [to Davao City, from Japan]. Everybody was asleep [and] snoring. A voice said, ‘You know, if you don’t stop [cursing], I will bring this plane down now.’ I said, ‘Who is this? Of course, it’s God. So I promised God not to express [my thoughts with] slang and cuss words.”

“You guys hear me right because a promise to God is a promise to the Filipino people,” said Duterte, transcript of which was sent to the presidential palace in Manila on Friday.

“Don’t clap too hard. It [your enthusiasm] might derail my promise,” said Duterte.

“There’s always a time; a time to be foul-mouthed [and a time to be speaking like a holy man],” said Duterte when asked if he would no longer cuss when talking about the United States, the European Union, and Senator Leila de Lima.

The US and the EU have threatened to cut aid for the continuation of his campaign against drug menace which has killed thousands since July.

De Lima, suspected to have abetted drug trading at the maximum security of the National Bilibid Prison in Metro Manila’s suburban Taguig has accused Duterte of committing extra-judicial killings in his campaign against illegal drug trade.

“I don’t like anybody reading my mind. It’s [my language is] all calibrated, it’s always [done with proper] timing,” said Duterte, in defence of his profanity-laced expressions when responding to critics and foes.

At the same time, he said, “If you know me the way my childhood friends know me, [they really know what is in my heart despite my curses]. We’ve been together for a long time. It’s like Superman [saying], I can read your mind.”

Earlier, he promised to give money to the coffers of a Catholic Church in Davao City, his hometown in the south, for every unstoppable curse. Duterte has not reported to the people how much he has paid for every curse since he sat in office in July.

He has called United States President Barack Obama “son of a bitch.”

He has made fun of United Nations Secretary General Ban Ki-moon, calling him “Ban Ki-sun”. “You’re another fool,” Duterte said when the UN chief gave statements about alleged human rights violations in the Philippines campaign against illegal drug trade,

He called outgoing US Ambassador to the Philippines Philip Goldberg, “bakla (homosexual).” – the US envoy criticised Duterte’s “rape joke” about being first with a lay Australian missionary who was raped and killed during a hostage taking in a prison in Davao City in 1989.

He also called former Interior Secretary Mar Roxas, a presidential candidate in the May 2016 polls “bakla,” because he was allegedly afraid to die in fighting crimes.

Instead of calling the followers of former President Benigno Aquino just “yellow,” the political colour of the Aquino administration, Duterte added “jaundiced,” an adjective to discredit the past administration.

In November 2015, during a campaign trail, he cursed Pope Francis for causing traffic in Metro Manila, during a visit in January 2015.