Commentary for Berakhot 11:11

ומנין לשנים שיושבים ועוסקין בתורה ששכינה עמהם שנאמר (מלאכי ג, טז) אז נדברו יראי ה' איש אל רעהו ויקשב ה' וגו'

And whence is it that when two sit and occupy themselves with Torah, the Shekinah is in their midst ? As it is said, "Then they that feared the Lord spoke one with another; and the Lord hearkened and heard, and a book of remembrance was written before Him for them that feared the Lord and that thought upon His name" (Mal. iii. 16).

Abraham Cohen Footnotes to the English Translation of Masechet Berakhot