וְאִם־מִזְבַּ֤ח אֲבָנִים֙ תַּֽעֲשֶׂה־לִּ֔י לֹֽא־תִבְנֶ֥ה אֶתְהֶ֖ן גָּזִ֑ית כִּ֧י חַרְבְּךָ֛ הֵנַ֥פְתָּ עָלֶ֖יהָ וַתְּחַֽלְלֶֽהָ׃
And if thou make Me an altar of stone, thou shalt not build it of hewn stones; for if thou lift up thy tool upon it, thou hast profaned it.
Read kabbalistic (mystical) interpretation of Exodus 20:22: and classical mystical sources.