Reference for Rosh Hashanah 62:5
א"ל הנ"מ לענין עדות החדש דא"כ נמצאת מכשילן לעתיד לבא אבל הכא (משלי כב, ז) עבד לוה לאיש מלוה
against her. Said R'Ashi to Amemar: [Is this right] seeing that we have learnt: SHOULD THE HEAD OF THE BETH DIN BE IN SOME OTHER PLACE THE WITNESSES SHOULD STILL PROCEED ONLY TO THE PLACE OF THE ASSEMBLY? - He replied: This refers only to the testimony with regard to the new moon, and [the reason for it is that] if this<span class="x" onmousemove="('comment',' Viz., that they should go after the head.');"><sup>10</sup></span> [were to be insisted on], the result might be to put a stumbling block in their way for the future;<span class="x" onmousemove="('comment',' As the messengers will refrain from going to all this trouble in order to give evidence.');"><sup>11</sup></span>