Those who are familiar with the Aleinu know Zech 14:9 well. It reads in Hebrew:
vehayah YHWH lemelekh `al-kol-ha'arets bayom hahu' yihyeh YHWH 'echad ushemo 'echad.
The phrase I want to ask about is:
bayom hahu' yihyeh YHWH 'echad
The last two words are the same as the last two words of the Shema`. But here they appear with the word yihyeh, which is the 3rd person masculine singular imperfect from hayah. Hayah means be, frequently in the sense of becoming or happening and the imperfect is the common way of expressing future. Therefore this phase translates as:
in that day YHWH will be (or become) echad
Since the Shema` declares YHWH echad what does it mean to become echad in that day?
S
vehayah YHWH lemelekh `al-kol-ha'arets bayom hahu' yihyeh YHWH 'echad ushemo 'echad.
The phrase I want to ask about is:
bayom hahu' yihyeh YHWH 'echad
The last two words are the same as the last two words of the Shema`. But here they appear with the word yihyeh, which is the 3rd person masculine singular imperfect from hayah. Hayah means be, frequently in the sense of becoming or happening and the imperfect is the common way of expressing future. Therefore this phase translates as:
in that day YHWH will be (or become) echad
Since the Shema` declares YHWH echad what does it mean to become echad in that day?
S