ל 30 + ח 8 + ם 40 = 78 = 3 × 26, the Tetragrammaton three times over.
Meaning
Lechem is bread — the showbread of the sanctuary and the matzah of Passover — and its 78 is exactly three times the value of the Tetragrammaton, an identity the handlists quote because bread is the offering set out before the name. The word is also the second half of Bethlehem, 'house of bread', which the tradition reads messianically.