Reference for Bava Batra 200:5
ת"ר אין פוחתין משבעה מעמדות ומושבות למת כנגד (קהלת א, ב) הבל הבלים אמר קהלת הבל הבלים הכל הבל
R. Aha the son of Raba said to R. Ashi: What was their procedure? He replied unto him: As it has been taught; R. Judah said, At first they provided in Judea no less than seven halts and sittings for the dead in the [following] manner: [The leader called out after the escort had sat down on the ground]. 'Stand, dear [friends], stand up'; [and after they had walked for some distance he again called out]. 'Sit down, dear [friends], sit down'.<span class="x" onmousemove="('comment',' This is the conclusion of the answer to R. Aha's enquiry. ');"><sup>12</sup></span> They<span class="x" onmousemove="('comment',' The Sages. ');"><sup>13</sup></span> said unto him: If so,<span class="x" onmousemove="('comment',' That the entire ceremonial consisted only of the leader's directions and of sitting down and standing up. ');"><sup>14</sup></span>