Related for Chagigah 3:3
אוֹכְלִין אֳכָלִים נְגוּבִין בְּיָדַיִם מְסֹאָבוֹת בַּתְּרוּמָה, אֲבָל לֹא בַּקֹּדֶשׁ. הָאוֹנֵן וּמְחֻסַּר כִּפּוּרִים צְרִיכִין טְבִילָה לַקֹּדֶשׁ, אֲבָל לֹא לַתְּרוּמָה:
It is permitted to eat dry foods with unclean hands, with terumah, but not with kodesh. [This is the intent: It is permitted to eat dry foods of chullin with unclean hands, with terumah but not with kodesh, i.e., If one stuck food of kodesh into his friend's mouth with clean hands, the hands of the eater being unclean; or if he himself stuck such food into his mouth with a reed or a rod, and he desired to eat radish or onion of chullin with it, in which instance his unclean hands, which are of second-degree uncleanliness, do not make the chullin unclean, still, the rabbis decreed that he not eat them with kodesh, lest he touch the kodesh food in his mouth with his unclean hands. But in respect to terumah, even though unclean hands render it unfit, they did not establish this higher level, but assumed that he could take care and not touch it. "Dry foods" is stated, for if liquid were now upon them the liquid would become first-decree uncleanliness because of his hands and would make the chullin second-degree uncleanliness, so that when it touched the terumah in his mouth, it would render it unfit.] A mourner [who did not become unclean through (contact with the body of) his dead one] and one lacking atonement [one who immersed and whose sun set, but who did not yet bring his offerings] require immersion for kodesh, but not for terumah. [After he brings his offerings, if he wishes to eat kodesh, he must immerse. For since until now they were forbidden to eat kodesh, the rabbis required immersion. One who lacks atonement renders kodesh unfit by touching it. And a mourner, even though he may not eat it, does not render it unfit by touching it. And even though a mourner may not eat second-tithe, he is permitted to eat terumah, this being derived from (Leviticus 22:10): "And every stranger (i.e., non-priest) shall not eat the holy thing (terumah)" — "Strangeness" (disqualifies), and not mourning.]