The word וימאן is mentioned 3 times in Sefer Bereishis
Where Yaakov refuses to be consoled over the supposed death of Yosef (37:35)
Where Yosef refuses the advancement of Eishes Potifar (39:8)
Where Yaakov refuses to switch his hands' position on Ephraim and Menashe (48:19)
Much has been said about each individual וימאן, but is there a connection between these 3 incidents (more than simply involving Yaakov and Yosef), which could explain why they all use this specific word?