What is the ruling on eating lemons grafted onto a poppy tree, knowing that the original poppy tree does not bear poppies but lemons, and that the fruits of the poppy are known for their narcotic substances?

The lemon is grafted onto the bitter orange tree, sometimes called "khashkhash" in some regions of the Levant, which is completely different from the poppy flower from which opium is extracted. The bitter orange is a perennial citrus tree, and its fruit is spherical, reddish-orange, and sour. Therefore, it is permissible to eat lemons grafted onto a bitter orange tree.