Hebrews 9:12–10:4 characterizes the blood of the first covenant in four ways: as the blood of goats and calves (9:12), as the blood of goats and bulls (9:13), as the blood of calves and goats (9:19), and finally as the blood of bulls and goats (10:4). Despite the noun transpositions and shifts from μόσκος (“calf”) to ταῦρος (“bull”) in 9:13 and 10:4, the changes usually elicit little comment from interpreters. When the changes are noted, the differences are often attributed to the author’s imprecision or dwindling concern for the actual practice of Yom Kippur, which in Rahlfs’s LXX depicts χίμαρος (“he-goat”) and μόσκος, not ταῦρος and τράγος (“he-goat”), as the sacrificial animals used in Lev 16. The argument, however, is rarely brought into conversation with the greater LXX tradition and other Second Temple Jewish sources. I argue that these four phrases betray a continued interest in the practice of Yom Kippur and reveal a carefully crafted pattern that builds into a scriptural allusion to Isa 1:11 LXX. The allusion evokes Isaiah’s criticism of injustice and hypocrisy, tempering Hebrews’ denunciation in 10:4 of the Levitical cult.