Midrash su Salmi 73:16

And it came to pass at midnight (Ex 12:29)1. R. Tanchum of Jaffa in the name of R. Nunia of Caesaria explicated the following verse: And when I pondered how I might know this, it was wearisome in mine eyes (Ps 73:16) . David said, “No one can stand on the [moment of] midnight except for the Kadosh Baruch Hu . For me, [when I pondered how I might know this,] it was wearisome in mine eyes. Because no one can stand on the [moment of] midnight except for the Kadosh Baruch Hu, it is therefore said, “And it came to pass at midnight.”