Reference for Moed Katan 39:1

שכבר נתעסקו בו ברגל כללו של דבר כל שהוא משום אבל רגל מפסיקו וכל שהוא משום עסקי רבים אין רגל מפסיקו

as they have already done that Service towards him during the festival. As a general principle on this matter [it may be stated]: 'Whatever appertains to the mourner [himself],<span class="x" onmousemove="('comment',' I.e., the observance of formal mourning by the mourner.');">¹</span> that the festival interrupts,<span class="x" onmousemove="('comment',' Is deferred till after the festival.');">²</span>

Jastrow

Jastrow