To what extent is the narration attributed to Ikrimah authentic, which contains inappropriate language and is used by Christians as an argument, and which interprets His saying, the Almighty: "or those who have no sexual desire among men" as "the effeminate man whose penis does not get erect"?

According to Tafsir al-Baghawi, "those who have no desire" (ghayr uli l-irbah) refers to those who follow people for food and have no desire for women, or the foolish impotent man, or one who is unable to approach women, or the mentally deficient, or the castrated, or the effeminate (mukhannath), or the very old man, the impotent, and the eunuch.

The hadith mentioned in the question has been weakened by scholars due to the presence of Hafs ibn Umar al-Adani in its chain of transmission, who is considered weak by many muhaddithun (hadith scholars).

Whether the hadith is authentic or weak, it does not provide an argument for Christians or anyone else. The phrase mentioned has not been described by any linguist or eloquent speaker as inappropriate. In the Arabic language, "mukhannath" (effeminate) is used for someone who resembles women.

Even if it were deemed inappropriate, it originated from an infallible person, and Imam Malik's statement applies: "No one's words are accepted or rejected except the occupant of this grave" — meaning the Prophet, peace be upon him.