In an emotional press conference, his first since confirmation on Thursday he would be leaving Goodison Park after 11 years, it was clear how much Everton means to Moyes. However the lure of Old Trafford was something he simply could not resist.
"I'm disappointed to be leaving such a great club," he said. "The club has been such a great part of my life."
But when asked if he had considered turning down United's approach, Moyes said simply: "I have to be honest and say no."
The Toffees manager's contract was due to expire in the summer but he claimed he wasn't planning to leave prior to signing a six-year contract to succeed Ferguson, who retires at the end of the season.
He said: "I wasn't planning on leaving. My contract was running out but we were planning for pre-season. All we've ever done here is keep planning."
Moyes added: "The fans have been great to me from day one here. I would like to say thank you for that support they've always given me.
"It was very difficult meeting with the chairman this week. I have great respect for him and we've had a great relationship.
"The chairman has never been critical of me and he has always tried to give me everything he possibly can to support me.
"The chairman has been really good for me and he will be really good for the next manager because he is a great chairman.
"I think Sunday will be emotional because I've been so close to the players and the people around Goodison.
"As a manager I might have got more mellow. I hope I've not lost that intensity but maybe learned to use it in the right ways."
Neil Lennon is favourite to succeed Moyes as Toffees manager, but the former Preston manager believes there will be many candidates considering applying for the role.
"I'm sure there will be lots of good people interested in this job and no wonder, because it is a great place to work.
"Whoever comes in (as manager) will get a well-run club, great set of players. I'm disappointed to be leaving such a great club.
"This club when I took over was bobbing along near the bottom of the PL. Now we're competing around 5th 6th spot every season.
"When I came in and mentioned the people's club it was from my heart how I felt about the club. The 11 years haven't disappointed me.
"The players this year have been exceptional and I would hate to think Sunday and next week are about David Moyes."