AT-TAGHABUN. التغابن
“Mutual deceit.’ The title of the 64th Surah of the Qur’an the IXth verse of which begins thus: “The day when He shall gather you together for the day of the assembly will he the day of Mutual Deceit”.
That is, when the blessed will deceive or disappoint the damned by taking the places which they would have had in Paradise had they been true believers, and vice versa.

Based on Hughes, Dictionary of Islam