Reference for Pesachim 233:21
אמר רב חסדא הללויה סוף פירקא רבה בר רב הונא אמר הללויה ריש פירקא אמר רב חסדא חזינא להו לתילי דבי רב חנין בר רב דכתיב בהו הללויה באמצע פירקא אלמא מספקא ליה
R'Hisda Said: Hallelujah marks the end of a chapter; Rabbah B'R'Huna said: Hallelujah marks the beginning of a chapter.<span class="x" onmousemove="('comment',' Where a single 'Hallelujah separates two psalms (e.g., Ps. CXXXIV and CXXXV) , R. Hisda maintains that it ends the first, while Rabbah b. R. Huna places it at the beginning of the second.');"><sup>31</sup></span> R'Hisda observed: I saw that in the copies of the Psalms used in the college of R'Hanin B'Rab, 'Hallelujah' was written in the middle of the chapter,<span class="x" onmousemove="('comment',' I.e., the two men were into one with 'Hallelujah' in the middle.');"><sup>32</sup></span> which proves that he was in doubt.