A large medieval oil press, about 10 x 35 meters, was recorded NW of the village in 1947 by representatives from the Palestine Antiquities Department.

[7][8] In 1838 Beit Mahsir is noted as a Muslim village, located in the District of Beni Malik, west of Jerusalem.

The people thought it was enemies who did it, and one evening they hid themselves, and saw the rider, [..] He asked them what they wanted, and they told him: 'If thou art the 'Ajami, show us thy lands.'

"[13] Baldensperger later recounted the meeting with a Dervish who had stayed "with 'Ajami" (apparently a mythical creature) at the 'Ajami shrine above Bayt Mahsir.

[20] The villagers took pride in the fact that the last imam of its mosque, Shaykh Khalil As'ad, was a graduate of Al-Azhar University in Cairo.

[21] During the April–May fighting in the Jerusalem Corridor (operations 'Nachshon', 'Harel', 'Yevusi' and 'Maccabi'), Palmach units more or less systematically levelled Qastal, Qalunya and Khulda, and largely or partly destroyed the villages of Beit Surik, Biddu, Shuafat, Beit Iksa, Bayt Mahsir and Sheikh Jarrah.

[4][23][24][25] Two days later, on May 13, Israeli troops contaminated the village wells with a biological warfare agent consisting of typhus and diphtheria bacteria, as part of a programme to render Palestinian resettlement impossible and ensure 'the destruction of its ability to constitute an economic and military base for enemy forces surrounding the road.