Toney, who featured for Gareth Southgate's England squad at Euro 2024, was seen in London on deadline day undergoing a medical.
The now-former Brentford frontman was nearing the end of his contract, and the Bees had resigned themselves to his departure, with several Premier League clubs showing interest in the England international.
Despite interest from the likes of Chelsea, Arsenal and Manchester United, no formal offers were made for the 28-year-old, leaving the door open for the PIF-owned outfit to pounce, and they secured his services in the early hours of this morning.
Brentford confirm Toney departure
Brentford confirmed Toney's departure on the club's website this morning, and it is understood that the 27-year-old striker will pocket in the region of £16m per year in the Middle East.
The Bess' boss Thomas Frank said: "It's been a pleasure to work with Ivan over the last four years. He has averaged more than one goal every two games, which is an unbelievable number.
"On the pitch, he has been a fantastic goalscorer, link-up player and leader. He has pushed the team, the squad and himself. It's a wonderful journey that we have been on together. Ivan helped the club and the team, and the club and the team have helped Ivan.
"I'm happy he has an opportunity to try something new in his life and career. We thank him for so many magic moments and wish him all the best for his next chapter. Ivan leaves as a Brentford legend."
Toney did not feature for Brentford this season, having been excluded from all three of Frank's matchday squads across all competitions.
The England international scored 72 goals in 141 appearances for Brentford, spanning three Premier League seasons and one in the Championship.
Bees announce new full-back arrival
Brentford also got a bit of deadline day transfer business over the line, signing full-back Jayden Meghoma from Southampton.
The defender has signed a four-year contract at the Gtech Community Stadium, with the club holding an option to extend the agreement by an additional two years.
Meghoma became the Bees' fifth first-team signing of the summer, after Igor Thiago, Fabio Carvalho, Sepp van den Berg, and Gustavo Nunes.
The 18-year-old came through the Tottenham Hotspur youth ranks before joining Southampton Under-21s, and it is understood that Brentford paid in the region of £4m to secure his services.