Is the prayer of one who has not performed ghusl from janabah until after months valid, and must he make up the missed prayers that he prayed without ghusl?

The prayer of a person in a state of ritual impurity (janabah) is not valid until they perform ghusl (ritual bath), due to the Almighty's saying: "And if you are in a state of janabah, then purify yourselves." Therefore, whoever prayed while in a state of janabah for months must repeat all those missed prayers. The important thing is that they make them up while in a state of purity. And it is obligatory to make up missed prayers immediately without unjustified delay.