But when you see the abomination of desolationa standing where he should not be (let the reader understand), then those who are in Judea must flee to the mountains, Bible see other translations
From Dan. 9:27; 11:31; 12:11

“standing where he should not be.” The translations differ as to whether the text should read, where “he” should not be, or where “it” should not be. Some translations support “he” (ASV; ESV; NAB; NLT), while others support “it” (CJB; HCSB; NASB; NET; RSV). The grammar can be argued either way, as anyone who reads a few commentaries on the verse will discover.a Blass and Debrunner point out that a masculine participle referring to a neuter noun can designate a person.b

Since the grammar can legitimately be “he” or “it,” the meaning of the verse must be interpreted from the scope of Scripture. The “abomination of desolation,” which is referring to an abomination that causes desolation, is not a statue, but a person. Furthermore, not a historical person such as Antiochus Epiphanes (although he may have been a type for the Antichrist), but a person who will be manifested in the last days, whom we know as the Antichrist or Man of Lawlessness (2 Thess. 2:3ff), who goes into the Temple of God to show that he is a god.

Cp. Lenski; The Interpretation of St. Mark’s Gospel vs. William L. Lane, The Gospel According to Mark [NICNT].
Blass and Debrunner, A Greek Grammar of the New Testament and Other Early Christian Literature, ⁣¶ 34.

Commentary for: Mark 13:14