Positive commandment · Mitzvat Aseh #147 of 613
To cover the blood of beasts and fowl [which are slaughtered]
לכסות דם חיה ועוף
The verse · Vayikra 17:13
וְאִישׁ אִישׁ מִבְּנֵי יִשְׂרָאֵל וּמִן־הַגֵּר הַגָּר בְּתוֹכָם אֲשֶׁר יָצוּד צֵיד חַיָּה אוֹ־עוֹף אֲשֶׁר יֵאָכֵל וְשָׁפַךְ אֶת־דָּמוֹ וְכִסָּהוּ בֶּעָפָר
“And whatever man there be of the children of Yisra᾽el, or of the strangers that sojourn among you, who hunts venison of any beast or bird that may be eaten; he shall even pour out its blood, and cover it with dust.”
The Rambam’s words
To cover the blood of beasts and fowl [which are slaughtered], as [Leviticus 17:13] states: "And you shall pour out its blood and cover it with dust."
לכסות דם חיה ועוף, שנאמר: "ושפך, את דמו, וכיסהו, בעפר" (ויקרא יז,יג).
Why · Sefer HaChinuch #187
Covering the blood
“It is from the roots of the commandment [that it is] because the soul is dependent upon the blood, as we said about the prohibition of blood (Sefer HaChinukh 148).”
Who & when
“And [it] is practiced in every place and at all times by males and females.”
Where in the Mishneh Torah
Hilchot Ritual Slaughter הלכות שחיטה