Charles Ellicott Commentary Mark 12:29

"Jesus answered, The first is, Hear, O Israel; The Lord our God, the Lord is one:" — Mark 12:29 (ASV)

Hear, O Israel; The Lord our God is one Lord.—The quotation is given more fully by St. Mark than by St. Matthew. The opening words were in common use under the name of the Shemà (the Hebrew for “Hear”), and formed the popular expression of the faith of Israel. To say the Shemà was a passport into Paradise for any child of Abraham.