申命記 6:4

ה׳ אלהינו ה' אחד means, The Lord who is now our God and not the God of the other peoples of the world, He will at some future time be the One (sole) ה׳, as it is said, (Zephaniah 3:9) “For then I will turn to the peoples a pure language that they may all call upon the name of the Lord", and it is further said, (Zechariah 14:9) “In that day shall the Lord be One (אחד) and His name One" (cf. Sifrei Devarim 31:10).

שְׁמַ֖ע יִשְׂרָאֵ֑ל יְהֹוָ֥ה אֱלֹהֵ֖ינוּ יְהֹוָ֥ה ׀ אֶחָֽד׃

Hear, O Yisra᾽el: The Lord our God; the Lord is one.