Is it necessary to perform ablution again after ghusl?
As ghusl includes ablution, one does not need to perform ablution again. Because Aisha narrated that the Messenger of Allah (saw) did not perform minor ablution separately after the ghusl (Tirmidhi, Taharah, 79). Also, Abdullah ibn Umar expressed that ablution is not needed after ghusl by saying, “Which ablution is more comprehensive than ghusl!” (Tabarani, al-Mu’jam al-Kabir, XII, 371)
Source: Presidency Of Religious Affairs The Turkey, High Board of Religious Affairs FATWAS