Egypt star Salah has been linked with a move to the Gulf State for several weeks and it is believed a verbal offer was made to Liverpool by Al Ittihad on Friday.
The bid is understood to have been £100 million up front with a further £50 million in add-ons.
However, the Premier League club are determined to keep Salah and plan to reject all offer no matter the size of the fee.
Salah, who joined Liverpool from Italian side Roma in 2017, signed a new three-year contract with the Reds last year.
His agent had publicly ruled out a switch to Saudi Arabia during the close-season amid a host of Premier League stars opting to accept lucrative offers from the Gulf State.
"Mohamed remains committed to Liverpool," Salah's representative Ramy Abbas Issa said in August.
"If we considered leaving Liverpool this year, we wouldn't have renewed the contract last summer."
Salah has scored 138 goals in 221 appearances during six seasons at Anfield, winning the Premier League Golden Boot on three occasions.
Even if Liverpool had considered the possibility of life without Salah, the bid's arrival just before Friday's 2200 GMT transfer deadline would have left them with little time to find a replacement.
Asked on Friday about Salah's future, Liverpool manager Jurgen Klopp told reporters: "The position remains the same, absolutely. No doubt about that.
"We cannot (sell Salah). That's how it is. Nothing else to say."
