Adam Clarke on Hosea 13:2

And now they sin more and more - They increase in every kind of vice, having abandoned the great Inspirer of virtue.

Let the men that sacrifice kiss the calves - This was the test. If there be a Jew that pretends to sacrifice, and whose conversion is dubious, let him come openly and kiss the calves. This will show what he is; no real Jew will do this. If he be an idolater, he will not scruple. This was the ancient method of adoration.

1. They kissed the idol.

2. When the statue was too high or too far off, they presented the hand, in token of alliance.

3. They brought that hand respectfully to their mouths, and kissed it.

This was the genuine act of adoration; from ad, to, and os, oris, the mouth. So Pliny, Hist. Nat., lib. xxviii., c. 1. Adorando, dexteram ad oscula referimus.

And Apuleius, Asin., lib. iv:

Admoventes oribus suis dexteram, ut ipsam prorsus deam religiosis adorationibus venerabantur.

See Calmet, and see the note on Job 31:17.