I noticed that some siddurim have the text “Hashkiveinu, Hashem Elokeinu” – Lay us down to sleep, God, Our Lord” in the closing blessing of the evening Shema, while others change the text from “Hashem, Elokeinu” – “God, Our Lord” – to Avinu – Our father. A.T.

The Ari HaKodesh changed the text from “God, Our Lord”, to “Our Father” because he felt that it is inappropriate to lay down to sleep in the presence of God as Lord. It is only appropriate to lie down to sleep in the presence of God as our Father.