Ah, yes.
Acts 15:20 But that we write to them, that they refrain themselves from the pollutions of idols, and from fornication, and from things strangled, and from blood.
Acts 15:29 That you abstain from things sacrificed to idols, and from blood, and from things strangled, and from fornication: from which things keeping yourselves, you shall do well. Fare ye well.
Haydock Commentary on Acts 15:20, 29
Ver. 20. Things strangled and from blood.
In these prohibitions, the Church indulged the particular feelings of the Jews, that the bond of union between them and the Gentiles might be more closely united; the latter in these two instances giving way to the prejudices of the former, who in their turn gave up much, by submitting to the abolition of the ceremonial law of Moses. This prohibition was of course only temporary, and to cease with the reasons, which gave rise to it. (Menochius)
— The Jews had such a horror of blood, that they considered those who eat it as defiled, and violators of the law of nature. The Lord had in effect from the beginning forbidden the use of blood to Noe [Noah], (Genesis ix. 4.) which he likewise reported in the strongest terms in Leviticus viii. 26.[vii. 26.?] By this we see the great authority of God’s Church, and Councils which may make permanent or temporary decrees, such as are fitting for the state of the times or peoples, without any express Scripture at all, and by this authoritative exaction, things become of strict obligation, which previous to it, were in themselves indifferent. (Bristow)
Ver. 29. From blood, and from things strangled.
The use of these things, though of their own nature indifferent, were here prohibited, to bring the Jews more easily to admit of the society of the Gentiles; and to exercise the latter in obedience. But this prohibition was but temporary, and has long since ceased to oblige; more especially in the western churches. (Challoner) — See note on ver. 20, above.