1 Kings 17:4-6

I find this interesting.

[1 Kings 17:4-6 NKJV] 4 "And it will be [that] you shall drink from the brook, and I have commanded the ravens to feed you there." 5 So he went and did according to the word of the LORD, for he went and stayed by the Brook Cherith, which flows into the Jordan. 6 The ravens brought him bread and meat in the morning, and bread and meat in the evening; and he drank from the brook.

[Leviticus 11:13-19 NKJV] 13 'And these you shall regard as an abomination among the birds; they shall not be eaten, they [are] an abomination: the eagle, the vulture, the buzzard, 14 'the kite, and the falcon after its kind; 15 'every raven after its kind, 16 'the ostrich, the short-eared owl, the sea gull, and the hawk after its kind; 17 'the little owl, the fisher owl, and the screech owl; 18 'the white owl, the jackdaw, and the carrion vulture; 19 'the stork, the heron after its kind, the hoopoe, and the bat.

Abomination: שָׁקַץ shâqats, shaw-kats'; a primitive root; to be filthy, i.e. (intensively) to loathe, pollute:—abhor, make abominable, have in abomination, detest, × utterly.

Not only were ravens unclean but they were also an abomination; yet, God sent them to feed Elijah.

Abominations can be used for good purposes by God.

[Leviticus 7:19 NKJV] 19 'The flesh that touches any unclean thing shall not be eaten. It shall be burned with fire. And as for the [clean] flesh, all who are clean may eat of it.

But when did the ravens truly become unclean?

[Leviticus 5:2 NKJV] 2 'Or if a person touches any unclean thing, whether [it is] the carcass of an unclean beast, or the carcass of unclean livestock, or the carcass of unclean creeping things, and he is unaware of it, he also shall be unclean and guilty.

When they were dead. These were living ravens that brought food to Elijah. So, you see, the ravens were to feed Elijah and were not unclean as servants to him.