Reference for Sanhedrin 172:1

להלקותו באנו והני אחריני כולי דבר קא עבדי ליה

'We came [merely] to have him flogged', and therefore these last witnesses attest the whole offence [involving execution].<span class="x" onmousemove="('comment',' V. supra 71a. It is there stated that he was first warned in the presence of three, and then flogged (on the testimony of two witnesses), and only if he offended again is he executed. The second offence too, of course, must be attested by two witnesses. Now, if these last two were proved zomemim, Hezekiah admits that they are executed, for their testimony is complete in itself, in so far as it imposes an additional punishment, as explained here. ');">¹</span>

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