What is the meaning of "va'Hamisheni"?
Rashi: He will make me feel [where is the pillar]. This is like "Ulai Yemusheni" (Bereishis 12:12).
Radak: The root is Yamash, i.e. removal, like "Lo Yamish Amud he'Anan", "Lo Yamish mi'Toch ha'Ohel" (Shemos 13:22, 33:11). However, (a) those verbs are Omed (the action applies to the subject himself), and this is Yotzei (he acts on others), and (b) those denote distancing, for they are followed by the prefix Mem, and this denotes coming close, for it is followed by Es, which is like El regarding places.
What is the meaning of "Es ha'Amudim"?
Radak #1: It is like El ha'Amudim, and similarly "v'Es Beis Hashem Ani Holech" (19:18).
Radak #2: According to those who explain va'Hamisheni to mean feeling, Es is like the simple meaning (it denotes the direct object; in English, it is not translated).