A convicted terrorist exchanged 1,000 messages with the Manchester Arena bomber Salman Abedi in less than a month, the inquiry has heard.
Abdulraouf Abdallah was read texts about martyrdom and "maidens of paradise" in heaven, as the Inquiry heard the pair exchanged up to 40 messages a day.
Abdallah told the hearing into the 2017 attack that he denied playing any part in grooming Abedi into an extremist mindset before he detonated a bomb at the end of an Ariana Grande concert, killing 22.
The 28-year-old told the Inquiry the chat was "nothing to do with extremism or terrorism" and was instead about friends who had died in conflict.
Paul Greaney QC, counsel to the Inquiry, asked: "In those messages, or some of them, were you grooming or seeking to groom Salman Abedi into an extremist mindset?"
Abdallah said: "No, I don't even have an extreme mindset myself. My fight from the start was against Gaddafi and (Syrian leader) Assad so I'm not a groomer. I was not grooming Salman or anyone."
Mr Greaney went on: "Do you accept that the type of discussion you were having with Salman Abedi played at least a part in what caused him to become radicalised?"
Abdallah said: "I never knew that he was radicalised. I didn't play any part of radicalising."
Inquiry chairman Sir John Saunders asked: "Did you ever have any suspicion that he would become a suicide bomber?"
Abdallah replied: "No, no way. Not me or my friends or anyone had any idea what was going on in Salman's head."
Abdallah's Libyan family fled the murderous regime of Colonel Gaddafi in the early 1990s and were granted asylum in the UK where they moved to South Manchester, along with Abedi's family who were also anti-Gaddafi.
In July 2016, Abdallah received an extended sentence of nine-and-a-half years, with a custodial term of five-and-a-half years, after he was convicted of preparing and funding acts of terrorism by helping four men from Manchester travel to Syria where three of them fought for so-called Islamic State (IS).
His mobile phone was seized when he was arrested in late November 2014 on suspicion of those offences and later analysis revealed more than 1,000 message exchanges with Abedi.
Abedi visited Abdallah in jail in the months before the attack.
He said when he learned of the news in prison that his friend was the bomber, he was "crying, confused and shocked".
Abdallah said: "It's something that I can never, ever, ever take out of my mind and it is haunting me until now because he is my friend.
"I got convicted, went to prison and I was busy with my life. I have seen him twice after my conviction, in prison, and called him a couple of times but he only answered twice and that's all I know.
"Until now it's haunting me. It's still going in my head now. Why? When? How come?"
Asked for his view on reports that Abedi wanted revenge over the UK Government's role in killings in Syria and Iraq, he said: "If I had seen the slightest of that thing myself ... the truth of the matter is me and my boys will actually slap the hell out of him.
"If we had seen that side of him before we would have told his mum straight away."
Earlier in the Inquiry, Detective Chief Superintendent Simon Barraclough, the senior investigator into the Arena attack, said he thought it was likely that no one individual or circumstance led to the radicalisation of Abedi.
His team's investigation into Abdallah concluded any assistance he is suspected to have provided was likely to have been ideological motivation and encouragement, while no evidence had arisen to show any direct involvement in the planning of the bombing.
A radicalisation expert instructed by the inquiry has concluded Abdallah did groom Abedi into a "violent Islamist extremist worldview", and will give evidence later in the inquiry.
Abdallah, a paraplegic who was injured fighting against Gaddafi forces in the 2011 Libya uprising, unsuccessfully appealed against his sentence and maintains his innocence.
He also denies any involvement in or knowledge of the arena attack.