Altar of Stone

"The Altar is the means of establishing peace between the people of Israel and their Father in heaven; therefore, iron, which is used as an instrument of murder, should not be swung over it. What a guaranty for those that endeavor to establish peace between man and man, and between nations and nations, that no evil shall befall them!" said Johanan ben Zakkai (Mek., Yithro, 11; Tosef., B. Ḳ. vii. 6). And in the same spirit he said: "If the altar of the Lord must be built of whole stones (according to Deut. xxvii. 6), all the more should the men that perform the peaceful work of divine instruction be whole-souled and peaceful" (ib. 7). In a similar strain: "If the very stones of the altar are to be treated with respect and with decorum, how much more living man!" (Mek. l.c., end).

Jewish Encylopedia of 1906